Paint Your Town Beautiful…with Chemistry National Chemistry Week Planning Committee Cleveland Section

An Educational Hands-On Demonstration Program for Groups of 25 Students in Grades 3-6

Prepared by the

National Chemistry Week Planning Committee

of the

American Chemical Society

Cleveland Section

for

National Chemistry Week 2015

Called

Paint Your Town Beautiful…with Chemistry

Overview

Let's pretend we are no longer students, but paint chemists! During this program we will explore what makes paint so colorful. By looking at the names of paint chips provided by Sherwin

Williams (a Cleveland original), we see how much fun chemists must have in naming their paint colors! And at the end of the program, we will name our own paint color. We will make colored chalk using Day-Glo paint (another Cleveland specialty). We will make pigments, and study dyes that color clothing. Going beyond paint, we will see how color helps chemists (for example, by identifying acid levels in foods, and decoding a secret message). Chemistry indeed colors our world!

Note: After Sept. 1, 2015, please see our Cleveland Section web site (p. 3) for an Errata sheet.

Table of Contents Page

List of Experiments…………………………………………….. 2

How Experiment Write-ups are Organized………………… 2

Presentation Overview…………………………………………. 2

Websites of Interest……………………………………………. 3

Checklists………………………………………………………… 4

Supplies for Demonstrator to Bring from Home.…….……. 7

Supplies Included in Your Kit…………………………….…… 8

Experimental Setup………………………………………..……. 10

Greeting the Students and Opening Discussion………….... 14

Background for the Demonstrator (only)…………………….. 15

Road Map of Experiments……………………………………..... 16

Introduction for the Students…………………………………… 17

The Program……………………………………………………….. 18

Closing Session…………………………………………………… 33

Cleanup & Return Procedures……………………………......... 34

Appendices…………………………………………………………. 36

Addendum………………………………………………………….. 37

Acknowledgments

The National Chemistry Week (NCW) program of the Cleveland Section of the American Chemical

Society (ACS) began in 1994 with an idea to put together a scripted program that could be performed at any local school or library. This idea has expanded to become the centerpiece of the Cleveland Section's

NCW activities. On numerous occasions it has received national recognition from the American

Chemical Society, including the ChemLuminary Award for Outstanding On-Going NCW Event , awarded in 2012. In 2015 the Cleveland Section’s volunteers will perform at least 40 demonstrations at libraries, schools, and other public sites.

Our NCW efforts reach many students each year because of various sponsors who have donated money, materials and/or services to the Cleveland Section specifically for National Chemistry Week. This year we acknowledge the Day-Glo Color Corporation for their donation of glow-in-the-dark fluorescent pigments and the Sherwin-Williams Corporation for providing paint chips. We would like to especially thank our partners at the Cuyahoga County Public Library (CCPL) for creating and distributing flyers and providing the facilities for this program. We further extend our sincere thanks to John Carroll University for hosting GAK Day ( G rand A ssembly of K its Day) and our Dress Rehearsal, to NASA’s Glenn

Research Center which printed this and other documents, and to our Cleveland ACS Section for its financial support.

Last and most importantly, we thank all the volunteers who donated their time and expertise. This library/school program and other NCW events are the result of the hard work of many dedicated and talented volunteers. It all starts with our local section NCW Planning Committee. The Committee recommends, tests, and reviews activities & experiments; writes this script including a story line to hold the attention of children; collects supplies and materials; prepares the kits; recruits sponsors and volunteers; contacts libraries and schools; and schedules demonstrations. Committee members include

Betty Dabrowski, Alex Fensore, Bob Fowler, Liz Herbell, Lois Kuhns, Helen Mayer, Vince Opaskar,

Peter Tsang, Marcia Schiele, Ed Schneider, Shermila Singham and Jay Xu. Additional credit and thanks is given to the many GAK Day volunteers including students from Baldwin Wallace, Case Western

Reserve, Cleveland State and John Carroll universities who gave up a Saturday in September to help count, measure and assemble all of the necessary materials for our demonstration kits. A final thank you goes out to the dozens of dedicated chemistry professionals and scientists who lead the presentations and activities in schools, libraries, and other public locations. Without them there would be no Cleveland

Section NCW program.

List of Experiments

1.

Glowing Chalk…………………………………… 18

2.

Which Fabrics Turn Color?.................................. 21

3.

Indicators of Different Types…………………… 24

4.

Appearing Ink……………………………………. 26

5.

Patriotic Colors…………………………………… 28

6.

Many Colors from One………………………….. 31

How Experiment Write-ups are Organized

Each experiment’s write-up is presented as follows:

1.

Experiment Purpose & General Methodology : Background on the Experiment.

2.

Introduce the Experiment: Suggestions for introducing the experiment to the students.

3.

Performance Details: How to perform the Experiment in detail.

4.

Conclusions: Suggested conclusions to draw from the Experiment.

5.

Technical Information (for the Demonstrator): This information is background info to help you understand what we’re trying to accomplish technically in the experiment. It certainly isn’t intended that you give these technical details to the students unless the students ask or request it.

Presentation Overview

This section describes the basic presentation technique used during the demonstrations. This is a guideline only as the technique may vary for some experiments. Make sure you follow the instructions given in each experiment. The program this year consists of 6 experiments.

•

For most experiments your demonstration and the student’s hands-on work are nearly simultaneous. You will lead them as they perform the experiment.

•

Please encourage multiple students to assist when an experiment is done as a group at a table.

•

Four experiments will be done by all students while the other two are group experiments to be shared by all of the students at each table.

National Chemistry Week 2015 - Cleveland Section

2

VOLUNTEERS

This year the NCW Committee will be videotaping the annual “Dress Rehearsal” demonstrations as they are presented at JCU. We’ll post this video on YouTube and the link to it on the

Volunteers page at our web site at http://www.csuohio.edu/sciences/dept/cleveland_acs/NCW/ as soon as we know. It can be found by searching YouTube for “Cleveland NCW 2015”. It will demonstrate this year’s NCW program in detail and may be viewed by anyone interested in hosting our program. Alternately, this script provides enough detail for a teacher or parent to perform the presentation. The Cleveland ACS and NCW Committee do not require background checks on its volunteers nor do we require formal educational/teaching experience from all of its volunteers.

MAKE SURE TO FOLLOW ALL DIRECTIONS IN EXPERIMENTS

If experiments have special safety concerns due to the materials being used, they will be listed in the section for that experiment. Eye protection should be worn at all times by everyone, and students should be specifically told to not touch their eyes. Some of the chemicals used this year are household chemicals, and some have been purchased from chemical distributors see p. 36).

Care should be exercised this year by all concerned because of the use of several dyes which can stain skin, clothing and other fabrics. If exposure to any chemical should occur, flush with water and report the incident to the librarian and parent. For skin contact, washing with soap and water may suffice. Websites for where to obtain a Material Safety Data Sheet (MSDS) [now SDS] are listed in the Appendix A and also on our NCW website below.

For information about the American Chemical Society’s NCW safety guidelines, visit www.acs.org/portal/Chemistry?PID=acsdisplay.html&DOC=ncw%5Csafetyguidelines.html

.

Websites of Interest

Cleveland Section: http://www.csuohio.edu/sciences/dept/cleveland_acs/NCW/

National American Chemical Society’s “National Chemistry Week” website: www.

acs .org/ncw

Note: At the time of this printing, the Internet video demonstrating this Colorful 2015 Program had not yet been posted. After about

October 15, 2015 please search YouTube for “Cleveland NCW 2015”.


3

Checklists

Presenter’s Guide

Check Lists

Activities To Do Well Before the Day of the Demonstration

Contact the Children’s Librarian and

•

Verify the date and time of your 1-hour program

•

Also schedule AT LEAST an hour before and an hour after your program for set-up and clean-up. Modify the setup time appropriately depending on how familiar you are with the materials in your kit and if you will have an assistant. Make sure the room will be available. Ask if someone will be available to assist with the Program: Setup, Demonstration and Cleanup.

Read through this script to familiarize yourself with the experiments and verify that you have all the items as listed in the kit contents.

If you’re using a pre-printed hard copy of the script, obtain the Script

Errata/Addendum Sheet which will be posted on our web page.

Contact Bob Fowler at jrfowler@cox.net

with any questions.

Collect the materials you need to bring with you to the demonstration. A materials list is on page 7. The librarian may be able to provide some of the items, but you need to call to verify that—do not assume that the library has what you need. Do NOT assume you can easily obtain water in the library; at some sites faucets are close to the sink bottom and allow little room for easily filling bottles or cups.

While not necessary, it’s recommended that you ask a friend to assist, and/or contact the Head Children’s Librarian well in advance to request a student assistant or librarian to be your assistant.

Having someone available to help setup the room before the program and collect trash as the program progresses can help keep supplies organized. That person can also assist if individual students need help with or have questions about the experiments.

If you wish to add other experiments or demonstrations into your program, you must contact the Head Children’s Librarian through your local librarian ahead of time to get approval. Be careful and think “safety first”. Neither the NCW

Committee nor the Cleveland ACS approves of any experiments added to this program, and you are responsible for your own actions.

Completed?

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Activities To Do about ONE WEEK BEFORE your program

Contact the Head Children’s Librarian who is helping you to coordinate our program:

 VERIFY that they limited registration to 25 students.

 Ask the room to be arranged with 5 student experiment tables with 5 chairs each, an additional front table for the presenter and a small side table/area for literature, photo permission forms, and goggles.

 Ask for all the experiment tables to be covered with newspapers and for extra paper towels for each table. Otherwise take newspaper and do this during setup.

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4

Checklists


 Ask about availability of demonstration materials from the list on page 7 (ex. paper towels, newspaper).

 Invite the librarian and/or student assistant to stay for the entire program. (They might even offer to be an assistant if given the opportunity.)

Activities To Do AT LEAST ONE DAY BEFORE the Demonstration

Read over the experiments a few times and become familiar with them . Our program is designed for about one hour for someone who is comfortable with the script. Practicing your presentation is very helpful. There’s very little in the way of Setup that needs to be performed beforehand at home this year.

Completed?

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Activities To Do When You Get To The Library

NOTE: Arrive at least 1 hour before show time to allow for introductions and set-up depending on how quickly you think you can perform the steps listed in the

Experimental Set-up section. DO NOT assume that a librarian will be present to help you set up for the experiments.

Introduce yourself to the Head Children’s Librarian.

Confirm that the tables and chairs are set up properly.

Confirm that all tables are covered in newspaper or have chemical/liquid resistant surfaces.

Obtain those supplies from the list on page 7 if provided by library.

Optional: Ask the Head Children’s Librarian or an assistant to take pictures WHEN

ABSOLUTELY EVERYONE IS WEARING GOGGLES during the demonstration (subject to parents/guardians having given permission to take the pictures).

Complete Experimental Set-Up; see page 10.

Set-up note!

If you follow the script as originally written, there are many cups and other items on the tables. Depending on the size of your tables, and the activity level of your students, you may choose to distribute fewer items originally. If so, then perhaps keep the remaining experiments’ material at your presenter’s table— on the plastic tray by an assistant if you have one—and distribute these items throughout the program.

Completed?

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 Set up an ‘Entrance’ area table to allow space for goggle distribution and fitting by the parents, photo permission form signing, and (at the end of the program) distribution of literature. Place copies of the ACS Celebrating Chemistry, the ACS

Photo Permission forms and any other literature on this table.

You may wish to set up an ‘Exit’ area table to allow space for end-of-program activities: goggle return and literature distribution.

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Activities To Do At the Start of The Demonstration

Ask the parent/guardian for permission to photograph the children for possible use on our website and obtain their signatures to this effect . If that permission is not

Timing

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5

Checklists

Presenter’s Guide obtained, make sure that that student is positioned in such a way in the room that they won’t be included in the photographs, or do not take any photographs. It is advisable to seat students with photo permission at the same table.

Hand out goggles and help adjust to the correct fit (if necessary). Tell the student to pull the air vents to the open position. Everyone must wear goggles at all times.

Activities To Do During The Demonstration

Activity/Experiment

Welcome & Introduction

Exp. 1: Glowing Chalk

Exp. 2: Which Fabrics Turn Color?

Exp. 3: Indicators of Different Types

Exp. 4: Appearing Ink

Exp. 5: Patriotic Colors

Exp. 6: Many Colors from One

Closing Comments

Collect goggles, hand out literature & thank everyone for coming.

Ask students to complete their Student Feedback forms

Type

Individual

Demonstration/Grp

Individual

Individual

Group

Individual

---

Total Time



Timing

Time (mins)

2

10

10

10

5

15

10

2

2

2

~60

Activities To Do Immediately After The Demonstration

Clean up as indicated in the Clean Up & Return section (p. 34).

Give the mailing envelopes (the Photo Permission , Student Feedback and

Demonstrator Feedback forms) along with the box of student and adult goggles to the librarian for return to Julia Boxler via interlibrary mail. (Those outside of the

CCPL network can return items to your nearest CCPL branch for return to Julia

Boxler-YTH. See www.cuyahogalibrary.org for branch listings.) Please return all materials within two weeks of NCW.

Give any leftover literature to the librarian (CCPL library kits only).

Activities To Do Once You Get Home

Email photos to Bob Fowler at jrfowler@cox.net

along with some text describing each.

Smile! You have just shared your joy of science and chemistry with children, possibly inspiring them to become great scientists, chemists, biologists, engineers...

Completed?

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Completed?

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6

Supplies for Demonstrator to Bring from Home


Supplies for Demonstrator to Bring from Home

Items for Presenter to Provide (or to request in advance from the librarian—do not assume that the library will have these materials)

1.

1 2-gallon plastic jug filled with tap water.

2.

A 4 cup or 1L Pyrex measuring cup.

3.

A ½ teaspoon measure

4.

1 large garbage bag for solid waste collection.

5.

1 bucket for liquid waste collection (optional if a sink is available within the demo room).

6.

Pens for parents to fill out photo permission forms.

7.

1 roll of paper towels.

8.

Some extra newspapers to put on the tables if the library hasn’t covered them for you.

Newspapers should also be available for placing under the dye tray on the demonstrator’s table.

9.

Extra newspapers should be brought along this year for use in disposal of dye solutions— see p. 34.

10.

A roll of masking tape to hold the newspapers flat on the tables.

Optional: IF you care to take pictures, bring a digital camera for doing so. Make sure students’ parents have given their permission for the children to be photographed on the ACS form and that the students and any adults to be photographed are ALL wearing goggles. You might want to assign the photography chores to an assistant during the demonstration. It is better to have close ups of one or a few students to show what they are doing and their excitement. Please send Bob Fowler copies of your pictures at jrfowler@cox.net

along with some text describing each.

Note : If you will be performing multiple demonstrations on the same day with the same goggles, you’ll need to sanitize them between demonstrations (refer to p. 34 for more information). For this you’ll need:

1.

small quantity of household bleach

2.

wash bin or bucket

3.

old towels or cotton paper towels for drying (soft so as not to scratch the goggles)… OR …individual sanitizer wipes (soft so as not to scratch the goggles).


7

Supplies Included in Your Kit


Supplies Included in Your Kit

General

1.

Materials for 6 Experiments—all in numbered plastic bags.

2.

1 copy of this script.

3.

1 9x12 manila envelope addressed to Julia Boxler – YTH containing 25 copies of the ACS

Photo Permission and Student Feedback forms and 1 copy of the Demonstrator Feedback form

4.

25 copies of Celebrating Chemistry 2015 for distribution.

5.

5 Dye Rating Forms

6.

25 golf pencils

7.

25 copies of a Student Handout (if available)

Also included (external to the kit box):

8.

1 box of goggles (25 student & 2 adult sizes, addressed for return to Julia Boxler - YTH )

Materials by Experiment:

Experiment 1: Glowing Chalk (Individual Experiment)

1.

26 pieces of 8½ x 5½” white paper.

2.

26 empty film canisters.

3.

25 50ml vials containing plaster of Paris marked P.

4.

25 4oz plastic cups marked C.

5.

25 4oz plastic cups marked W.

6.

1 sandwich bag containing 75g of fluorescent dye marked D.

7.

25 wooden stirrers.

8.

25 plastic spoons.

Experiment 2: Which Fabrics Turn Color? (Demonstration/Group Experiment)

1.

1 small 2x3 plastic bag labeled K containing Kool-Aid powder.

2.

1 small 2x3 plastic bag labeled R containing Rit dye.

3.

1 10ml vial labeled F containing a food color.

4.

1 10ml vial labeled V containing vinegar.

5.

1 16oz plastic cup labeled D1.

6.


7.


8.


9.

24 paper towels.

10.

4 plastic forks.

11.

4 plastic spoons

12.

1 pair of adult protective gloves

13.

20 ½” wide strips of ribbon fabric


8

Supplies Included in Your Kit


Experiment 3: Indicators of Different Types (Individual Experiment)

1.

5 small portion cups labeled 1.

2.


3.


4.


5.

1 50ml vial labeled 1 containing vinegar.

6.

1 50ml vial labeled 2 containing a baking soda solution.

7.

1 50ml vial labeled 4 containing a 0.1M borax solution.

8.

25 paper towels.

9.

100 Q-Tips.

10.

20 lined index cards which have been divided into 6 equal sections.

11.

1 vial of 100 strips of pH paper

12.

5 pH color scales.

Experiment 4: Appearing Ink (Individual Experiment)

1.

5 sets of 5 (3”X 5”) index cards separated by pieces of colored paper

2.

25 Q-Tips.

3.

25 portion cups labeled B.

4.

A recycled water bottle containing a basic solution marked B.

Experiment 5: Patriotic Colors (Group Experiment)

1.

10 50ml vials with the number 5 containing a CuSO

4

solution.

2.

5 10ml vials with the number 6 containing household NH

4

OH.

3.

5 10ml vials with the number 7 containing a 10% MEA solution.

4.

5 50ml vials with the number 8 containing a 0.1M KSCN solution.

5.

5 10ml vials with the number 9 containing a 0.1M FeCl

3 solution.

6.

5 50ml vials with the number 10 containing a 1M CaCl

2 solution.

7.

5 10ml vials with the number 11 containing a 1M NaHCO

3 solution.

8.

20 4ml beral pipettes.

9.

20 wooden stirrers.

10.

5 red, 5 blue and 5 white paint chips.

Experiment 6: Many Colors from One (Individual Experiment)

1.

50 Whatman #4 90mm filter papers.

2.

5 10ml vials marked either B, Y or G. It doesn’t matter which color it is as long as there is at least one of each

3.

5 10ml vials marked M.

4.


5.

25 paper towels.

6.

50 4” squares of waxed paper.


9

Experimental Setup



Note: In our preferred setup there are 5 places at all 5 student tables (i.e., 25 places total).

Only two experiments require items at the demonstrator’s table this year.

Overall

Before starting to lay out the materials for the experiments, please put one of the following at each student’s place :

1.

One golf pencil

•

At the center of each table place the following:

1.

One Dye Rating Form


•

At the demonstrator’s table place the following

1. A piece of 8½ x 5½” white paper.

2. 1 empty film canister.

•

At each station place the following:

1.

1 piece of 8½ x 5½” white paper.

2.

1 empty film canister.

3.

1 50ml vial containing plaster of Paris marked P.

4.

1 4oz plastic cup marked C. Put ½ teaspoon of the fluorescent dye powder in the sandwich bag marked D into each student’s cup marked C.

5.

1 4oz plastic cup marked W. Fill each cup marked W about ¾ full with tap water.

6.

1 wooden stirrer.

7.

1 plastic spoon.

Experiment 2: Which Fabrics Turn Color? (Demonstration/Group Experiment)

•

At the demonstrator’s table place the following

1.

A pair of adult-size protective gloves.

2.

4 paper towels.

3.

4 plastic forks.

4.

1 10 ml vial marked F containing food coloring.

5.

A small baggie marked K (containing Kool-Aid).

6.

A small baggie marked R (containing Rit dye)

7.

10 ml vial marked V (containing vinegar).


10



8.

Four 16 oz clear plastic cups marked D1, D2, D3, and D4.

9.

1 tray.

10.

4 teaspoons.

•


1.

4 test strips containing 13 different fabrics.

2.

4 paper towels.

3.

1 Dye Rating Form .

•

Do the following:

1.

Perform the following steps just before the program begins so that the dye solutions are still relatively warm when the fabrics are dyed.

2.

Put on the plastic gloves and be very careful with the dyes you’re about to create.

Hopefully the tray will contain any spills, but any of these dyes could permanently stain your clothes, your skin or the rugs.

3.

Put the tray onto the demonstrator’s table. Fold four of the paper towels in half lengthwise and lay them lengthwise in a row in the tray about 6“ apart.

4.

Place the cups marked D1 to D4 in a row at one end of each paper towel.

5.

Empty the contents of the small baggie marked K into the cup marked D1.

6.

Empty the contents of the 10ml vial marked F into the cup marked D2.

7.

Fill the 4 cup or 1L Pyrex cup with water and heat until very hot.

8.

Fill cups D1 and D2 (only) halfway with hot tap water.

9.

Stir the contents of each of these 2 cups ( with different teaspoons ) until thoroughly mixed.

10.

Put the contents of the small baggie marked R (containing Rit dye) into 16oz (~473ml) of hot tap water in the Pyrex cup and use another teaspoon to dissolve thoroughly.

11.

Fill each of the 16oz cups marked D3 and D4 halfway with the Rit dye solution from the

Pyrex cup.

12.

Empty the contents of the 10 ml vial marked V into the cup marked D4 and stir thoroughly.

Experiment 3: Indicators of Different Types (Individual Experiment)

•

Do the following:

1.

Fill each of table’s small portion cups marked 1 about 1/3 full from the 50ml vial marked

1.

2.


2.

3.

Fill each of table’s small portion cups marked 3 about 1/3 full of tap water.

4.


4.


11



•


1.

1 small portion cup labeled 1 containing a vinegar solution. Cover with a lined index card.

2.

1 small portion cup labeled 2 containing a baking soda solution. Cover with a lined index card.

3.

1 small portion cup labeled 3 containing tap water. Cover with a lined index card.

4.

1 small portion cup labeled 4 containing a borax solution. Cover with a lined index card.

5.

1 pH color scale

•

At each student’s place put the following:

1.

1 paper towel.

2.

4 Q-Tips.

3.

4 2” strips of universal indicator paper.


•


1.

1 3”X5” index card from the set of 5 cards which were separated by pieces of colored paper.

2.

1 Q-Tip.

3.

1 portion cup labeled B. Fill each student’s portion cup marked B about 1/3 full with the basic solution from the recycled water bottle marked B.


•


1.

2 50ml vials with the number 5 containing a CuSO

4

solution.

2.

1 10ml vial with the number 6 containing household NH

4

OH.

3.

1 10ml vial with the number 7 containing a 10% MEA solution.

4.

1 50ml vial with the number 8 containing a 0.1M KSCN solution.

5.

1 10ml vial with the number 9 containing a 0.1M FeCl

3 solution.

6.

1 50ml vial with the number 10 containing a 1M CaCl

2 solution.

7.

1 10ml vial with the number 11 containing a 1M NaHCO

3 solution.

8.


9.

3 paint chips: one red, one blue and one white

10.

4 wooden stirrers.


12




•


1.

1 10ml vial marked either B, Y or G. It doesn’t matter which color it is.

2.

1 10ml vial marked M.

3.


•


1.

2 round pieces of Whatman #4 90mm filter papers

2.

1 paper towel.

3.

2 4” squares of waxed paper.


13

Greeting the Students and Opening Discussion


Greet the Students (and Parents) Upon Their Arrival, Distribute

Goggles, and Organize the Seating

1.

If you plan to take pictures, ask the parents/guardians to give or withhold their permission for the student to be photographed via the ACS consent form. Don’t forget to obtain their signatures on the forms provided.

Note : You might want some librarian assistance with this: IF you plan to take photos and some of the parents have denied permission, you’ll want to put all of the children who aren’t going to be photographed at a separate table. The librarian may have separate but similar forms for the library’s use. Make sure to get the enclosed forms signed—do not rely on the library’s forms.

2.

Help the students or have the students’ parents put on their goggles. Adjust the straps as necessary. (Note: These goggles are sanitized each year and prior to each demonstration.)

Suggest that the students pull the air vents open for comfort while wearing the goggles.

3.

Distribute the students 3-5 per table. 5 students per table would be best.

Opening Discussion

Introduce the Items on the Tables :

•

Tell the students not to touch anything until told to do so and not to shake the table or things could fall over and the fun ruined. We have some dyes on the table, and these could stain clothing. Be careful!! Never taste or smell anything, as if they were in a laboratory!

•

Tell the students that various items have been gathered for them on their table. Most items in today’s program are common household items.

•

Put on a pair of the adult-sized goggles. If you have an assistant, ask them to do the same.

Verify that all students have goggles on.

Introduce Yourself and the Program

•

Introduce yourself as a chemist or science teacher/engineer (or state your interest in chemistry), and introduce the American Chemical Society as the largest organization in the world devoted to a single profession.

•

Introduce National Chemistry Week—what it is and why we do it. (Hint: it is a nationwide event put on by volunteers like you to let non-scientists know about chemistry, how much fun it can be and how it can improve our everyday lives.)

•

Please tell the students that we’d really like for them to vote for the experiment they liked most in today’s Program. At the end of the Program they’re going to have a chance to vote on their favorite experiment as well as the one that they think taught them the most. They’ll do this via the hardcopy Student Feedback form at their places. So tell them to remember what they like about each experiment.

•

Also tell them that they have a Student Handout at their place (if provided). Tell them to make sure they take it home because it has interesting info, a list of books to read, and links to do some of today's experiments at home.


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Background for the Demonstrator (only)


Background for the Demonstrator (only)

This year the NCW theme is Chemistry Colors our World . We’ve chosen to demonstrate how this happens in several ways:

1.

In Experiment 1 (Glowing Chalk) we’ll demonstrate how pigments, in particular glowin-the-dark fluorescent pigments, can be used to enhance ordinary items used by children such as chalk. The students will especially enjoy this one since they’ll be able to take their experimental results home with them.

2.

Experiment 2 (Which Fabrics Turn Color?) shows the students how chemists have developed different type of dyes which are used to color a variety of fabrics. We’ll find that classes of dyes color some fabrics better than others and that some fabrics aren’t affected by dyes at all.

3.

With Experiment 3 (Indicators of Many Colors) the students will learn how chemists use indicators which turn a range of different colors to measure pH.

4.

In Experiment 4 (Appearing Ink) they’ll see how chemistry might have been used back in the days of George Washington to send secret messages.

5.

Experiment 5 (Patriotic Colors) shows how our country’s colors can be created by chemistry and how shades of colors could be created. We compare shades of red, white and blue (and purple) with paint chips from Sherwin Williams here in Cleveland.

6.

Finally in Experiment 6 (Many Colors from One) the students will learn how chemists separate mixtures of colors into the component colors.

Paint chemists use both inorganic pigments and synthetic organic pigments. The inorganic pigments include the same ones used by cave men, like iron oxides for red and yellow, limestone or chalk for white, and carbon black. More modern inorganics include TiO

2

for white, etc.

Inorganics give paint many good qualities, but synthetic organic pigments give paint its multiple shades of beautiful colors.

Pigments are usually powders/materials that are dispersed and suspended in the paint. Dyes are usually liquid, in solution, and can be natural or synthetic.

There’s quite a bit more information on Color Theory, Pigments and Dye in the Addendum.

New this year is the Road Map of Experiment section (next). Since there’s a need to return to experiments after items have hardened, been dyed or separated into components and this tends to cause confusion, we’ve provided this road map to guide you through the maze. We suggest that you use this page as your main navigation tool while you’re presenting the experiments.


15

Road Map of Experiments


Road Map of Experiments

Here’s one item that may be useful to you. In Exp. 1 we have to wait about a half hour for the chalk to harden, in Experiment 2 we have to give the fabrics time to absorb the dyes and in

Experiment 6 we have to give the colors time to separate. After the chalk has sufficiently hardened in Exp. 1, we have to give the bare chalk (i.e., released from its paper cocoon) time to absorb some photons; then at the end of the program we’re going to darken the room as much as possible and demonstrate how the chalk does indeed glow. So we have to give things time to harden, absorb and separate; we realize that this is going to cause some confusion, but there isn’t much that can be done about it. Since we’re going to have to return to these experiments once or even twice, the Committee thought it might be useful to provide you with a “roadmap” of the sequences to be followed. Here’s how the Experiments will progress--you might want to use this page as your guide as your demonstration program progresses.

Sequence of Experimental events:

1.

Complete Part 1 of Experiment 1 [ Glowing Chalk ] (down to the point where the plaster is poured into the molds).

2.

Complete Part 1 of Experiment 2 [ Which Fabrics Turn Color?

] (down to the point where the fabrics are put into cups of dyes to soak.)

3.

Complete Experiment 3 [ Indicators of Different Types].

4.

Complete Experiment 4 [ Appearing Ink]

5.

Complete Experiment 5 [ Patriotic colors] .

6.

Complete Part 1 of Experiment 6 [ Many Colors from One] (down to the point all the filter papers have been impregnated with the dyes.)

7.

Complete Part 2 of Experiment 1 (remove paper cocoon and allow chalk to absorb light).

8.

Complete Part 2 of Experiment 2 (remove fabric samples from dyeing solutions & examine results of staining processes).

9.

Complete Part 2 of Experiment 6 (examine chromatographic results).

10.

Complete Part 3 of Experiment 1 (demonstrate how chalk glows in the dark).


16

Introduction for the Students


Introduction for the Students

Story Line :

Let’s pretend we are no longer students, but Paint Chemists! We will explore what makes paint so colorful. And at the end of this program, you will name your own paint color. By looking at the names on your paint chips, you can see how much fun the chemists must have in naming their paint colors! You will also make some colored chalk.

The Cleveland area, right here where we live, is a great place to be a Paint Chemist. We like to call Cleveland the Hub of the Color Wheel. There’s Sherwin-Williams in Cleveland. Paint wasn’t paint as we know it until Mr. Sherwin invented it. He and Mr. Williams founded their company in Cleveland in 1866. There is also Glidden, a paint company started in Cleveland in

1875. Day-Glo which makes daylight fluorescent and glow-in-the dark pigments was founded in

Cleveland in 1934. Another company, RPM, that makes Rust-Oleum is here in the Greater

Cleveland area in Medina, was founded in 1947.

We’re going to investigate lots of different ways we use chemistry to paint our world.

From here go to: Introduce the Experiment (#1) and then to Tell the students in order to continue the story line.

Experiment Purpose and General Methodology is a summary for the demonstrator not meant to be read to the students.


17

The Program-Experiment 1: Glowing Chalk



Experiment Purpose & General Methodology

For the demonstrator:

We’ll use green, aqua or blue fluorescent pigments to make Glowing Chalk. (You’ll have one of these colors in your kit.)

Introduce the Experiment

Tell the students :

Using different colors to paint is an idea that’s been around for a long time. The cave men painted. What materials did cave men use? Think of when you go camping. What’s around you? Rocks, minerals, dirt, fire, charred twigs from the fire, chalk (limestone).

Cave paintings were red from rocks that had iron oxides in them (rust is a type of iron oxide), yellow (also from rocks with iron oxides), black (from soot from a fire), and white (from chalk, white rocks).

These materials can be ground into powder and mixed with water or oil to make paint. These things that add color are called "pigments". We're going to use fluorescent pigments in this experiment. These absorb light during the day and then emit light or glow in the dark.

We’re going to use chemistry to make colorful chalk that the students can actually use to write on blackboards or to make hopscotch boards on the sidewalk in front of their home. The process whereby the chalk absorbs light and then glows in the dark is called fluorescence. We’ll be able to see this here in the room a little bit later because of the fluorescent pigments that we’re going to use.

Performance Details

Tell the students to do the following:

Part 1

Students start the experiment with the demonstrator showing them how to fold their piece of 8½

X 5½” in half lengthwise (each piece of paper is now 8½” X 2¾”). Show them how to wrap it around one of their fingers into a roll and place the roll into their round canister allowing it to expand to the canister’s diameter to form a paper “mold”. The paper should be manipulated until it has a uniform diameter—not like a funnel. Help students do this if needed.

Now ask students to remove the red cap from the 50 ml vial marked “P”. Noting that the 4 oz cup marked “C” already contains a small amount of a powder (the dye), pour the contents of the


18


Presenter’s Guide vial into the cup marked “C”. Before adding any water , carefully and thoroughly stir the two powders together with the stirring stick provided. Now add 4 teaspoons of water from the cup marked “W” and carefully stir the mixture with the stirring stick. We’re trying to get a slurry with the approximate consistency of ketchup. Add a little more water if necessary. Don’t make it too soupy or it won’t harden in time.

Once the student is satisfied with the slurry’s consistency, tell him/her to slowly and carefully pour it from the plastic cup into the center of the paper mold. While the chalk is hardening, move to Experiment 2 ; we’ll return to this experiment while we’re working on the final experiment.

Part 2

Remove the paper mold from the canister and peel the paper away from the chalk which should have hardened sufficiently by now. Ask the students to lay their chalk on the table fully exposed to light from all sources. Now return to and complete the last part of Experiment 2.

Part 3

Turn off the lights and close the curtains to darken the room as much as possible and ask the students what they observe. ( Ans .: the chalk should have a mild glow to it depending on the time of exposure to the light.)

Conclusions

Tell the students :

Notice that the chalk you’ve made is one of three different colors: green, aqua or blue. The colors are not really all that bright, but that’s OK because the chalk glows in the dark after it’s been exposed to light.

What caused the chalk to glow? The small amount of powder that was originally in their cups contained pigments which fluoresce when exposed to light. This means that these special pigments absorb light and then later give off light that’s not so bright; instead the chalk appears to glow or fluoresce. This is just one way that chemistry colors our world.

They can take their chalk home with them. Tonight they should expose their chalk to a light at home for a few minutes (any photons will do), turn off the lights in the room and then observe the Glowing Chalk. They can write something on the sidewalk during daylight, go outside after dark, shine a flashlight or porch light on it and they’ll see a slight glow.

In the next experiment we’ll learn about dyes.


19



Technical Information (for the Demonstrator):

Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation.

Nowadays synthetic pigments made by chemists have as important role as natural pigments.

Now, all pigments are either 1) natural or synthetic and 2) organic or inorganic chemicals

1

. "It is unlikely that there is any organic pigment, the naturally occurring form of which is still in industrial use today. Many inorganic pigments, however, are still dug out of the earth's crust, crushed, washed, etc. Frequently, there is a synthetic equivalent. The chief family of pigments in which natural varieties are still of importance, is the iron oxide family: ochres, umbers and siennas; red, yellow and black iron oxides." These sources are not all that different from those used by cavemen. " There are now far more organic pigments than inorganic ones , though some of the newest contain both metallic (inorganic) elements and organic structures." A list of pigment properties shows that inorganics give great white [TiO

2

] and black [carbon] paints, nonbleeding, lightfastness, heat stability, and anti-corrosive action. But organics give brilliance and clarity of hue! [And these organics have been developed and tweaked by paint chemists for use in today's beautiful colors.]

1 Intro to Paint Chemistry by Turner , ICI Paints, reprinted 1995.


20

The Program-Experiment 2: Which Fabrics Turn Color?


Experiment 2: Which Fabrics Turn Color? (Demonstration/Group

Experiment)



Chemists have created several classes of dyes including Acidic (e.g. Kool Aid and food dyes),

Direct ( RIT dyes) and Reactive dyes. Not all dyes color all fabrics, and some fabrics can’t be dyed easily at all. We’re going to test examples of the first of these two dye categories to see another way that chemistry colors our world.


Tell the students the following:

Early people made dyes. A dye changes the color of something….like the color of clothing or fabrics. Where did early people find dyes? Again think of nature….think of plants. Most natural dyes are from plants: berries, leaves, wood, bark, lichen.

Over the centuries chemists have created many different types of dyes. Food dyes can come from natural things like plants and oil, or synthesized (made) by food chemists. (Early dyes or stains for coloring cloth could fade and lose their color, they could react with other chemicals, and they were often delicate and translucent. Many people still like to use natural dyes. Today’s chemists have built on this technology and make dyes that are durable, permanent, uniform, have long shelf life, user-friendly…).

Today we’re going to see which dyes work best for several different fabrics. Each student must be wearing their goggles. It’s critical that they not spill the contents of cups D1 to D4. They contain dyes and will color their hands and clothes.

Performance Details:

Part 1

Demonstrator: First, put on your gloves and then please supervise the following closely. It will be a real problem if any of the students spill warm dye solutions on themselves, the library’s rug or you. Ask the students to pick a number, 1-5, and then call it off. Tell them to remember their number. Use these numbers when addressing the students to come up to the demonstrator’s table.

Divide these tasks among the students at each table.

1.

Going table by table, ask students 1-4 at each table to select a strip of test fabric and bring it to the demonstrator’s table when called up .


21



2.

While you’re watching closely, ask the number 1 students from all 5 tables to bring their fabric pieces to the demonstrator’s table and carefully slide his/her test strip into the cup marked D1. Stir this cup with the appropriate fork while the No.1 students are returning to their tables to make sure that all test strips are submerged and exposed to the dye in all the cups. After each use place the fork on the paper towel in front of the respective cup—please don’t mix them up and we’ll be using them again later. Repeat this process with cups D2-D4 on the demonstrator’s table with students 2-4 from all five tables. The

No. 5 students will have a special job a little later.

We’re now going to leave this experiment and go to Experiment 3 . We’ll come back in about ½ hour to complete Experiment 2.

Part 2

Now ask all the No. 1 students to come up to the demonstrator’s table each bringing a clean paper towel to retrieve their samples. They should do this as follows: each one in turn should lay their paper towel down on the demonstrator’s table. The demonstrator ( NOT the student!) should then use his/her appropriate plastic fork to fish one sample fabric strip from each cup and place it on the paper towel. The students should then pick up the paper towel by its corners, return to their place and lay the paper towel with the dyed test strip down at their place.

Repeat these steps for all 4 students at all tables.

Ask the No 5 student at each table to pick up the Dye Rating Form and his/her pencil. Each of the other students should now determine which of their thirteen fabrics accepted the dye they used starting with the dye in cup D1 through the dye in cup D4. Tell the students that they should take turns, starting with student No. 1 with the fabric from cup D1, and “rate” each of the fabrics starting from the left where the black dotted line is with a Y (for Yes) if the fabric was well dyed or a blank if it wasn’t. They should say these results out loud to student No. 5 in order, saying first the fabric number and then either “Y” or blank, starting from the left and continuing across the page to fabric 13. The No 5 student should record these results on the

Form starting in the upper left-hand corner with fabric 1 (acetate) and Dye 1 (Kool-Aid).

Conclusions

Ask/Tell the students the following:

What did they observe? ( Ans : not all fabrics accepted the dyes. Some dyes colored some fabrics while other dyes colored other fabrics.)

The students’ results should be similar to the following where the top row corresponds to the fabrics on the strip starting on the left--the black line on the fabric swatch indicates the left:


22



Dye

↓

1

Ace tate

2

SEF

2

3

Arnel

4

Bleached

Cotton

Yes

5

Creslan

61

6

Dacron

54

7

Dacron

54

8

Nylon

6.6

Yes

9

Orlon

75

10

Spun

Silk

Yes

11

Polyprop.

12

Vis- cose

3

Yes

13

Wool

Kool Aid

(D1)

Food

Color

(D2)

RIT

(D3)

Yes

Yes Yes

Yes

Yes

Yes Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

RIT +

HAc

(D4)

Yes Yes Yes

Ask the students the following:

Yes Yes Yes Yes

•

Which of the dyes was most effective? ( Ans : All four dyes were effective in coloring protein fibers such as wool and silk.)

•

Was one of the dyes most effective in coloring nylon? ( Ans : Yes, the acidic dye Kool-Aid

[D1] was most effective in coloring nylon.)

•

Was one of the dyes most effective in coloring Arnel and Viscose? ( Ans : Both acidic dyes

(D1 and food color [D2]) were most effective in coloring Arnel and Viscose.)

•

Which dyes were most effective in coloring viscose and cellulose fibers such as cotton?

( Ans : The direct dyes (RIT [D3] and RIT with vinegar [D4]) were the most effective in coloring viscose and cellulose fibers such as cotton.

•

In the last cup, D4, some vinegar was added to boost the dyeing power of the Rit dye. Did it make any difference? ( Ans : The dyeing effectiveness of Rit dye (D3) was enhanced slightly by adding vinegar (D4).)

•

If you were going to pick out a fabric for staining, which one would you buy? (Ans: The food color and Rit dyes (cups D3 & D4) were most effective in dyeing the most fabrics.)

•

Which dyeing job looks the best ( Ans : Probably the Rit dyes—cups D3 & D4)

Tell the students that they can take the dried, dyed fabric swatches home with them.

Return now to Part 2 of Experiment 6.


Please see the Addendum for technical info about dyes.

2

3

SEF: Self Extinguishing Fabric, a Modacrylic.

A form of Rayon.


23

The Program-Experiment 3: Indicators of Different Types


Experiment 3: Indicators of Different Types (Individual

Experiment)

The students will test the pH of vinegar (pH=3), water (pH=7), baking soda (pH=8), and 0.1 M borax (pH=9).


Tell the students :

In the Middle Ages, artists used the seeds of a certain flower to color pieces of cloth. This flower, from France, would turn its head to follow the sun. The artists would dip their cloths into the juice from the seeds and let them dry. Here’s the strange thing about this: when they later wetted the cloths they got different colors. If they used plain water, the cloth turned purple. If they used something like lemon juice (which is acidic) the cloth turned red. If they used something basic (or alkali) it turned powder blue. We really don’t use this flower anymore, but there’s a well-known algae that does the same thing (from Scandanavia). It’s found in every chemistry lab and it’s used to make “litmus” paper (which is the Norse word for “to color”). It turns red in acid, and blue in a base.

A lot of times Chemists are given an unknown material and they have to figure out what it is.

One of the first things a Chemist will try to do is figure out if the material is an acid, or a base.

We all have to be very careful if we ever come home and see an unlabeled liquid in a cup on the counter. We should never try to drink it! The liquid could be a STRONG acid, or a STRONG base which could really hurt us. It would be a Chemist’s job to figure out what the liquid in the cup is. Sometimes Mom is a great Chemist and helps us out with this.

Today we are going to do an experiment with some liquids that range from WEAK acids to

WEAK bases and work to tell the difference. Chemists use a special kind of Indicator Paper to tell if a liquid is an acid, base, or if it is neutral. This special paper is call pH paper. The pH scale ranges from 1 to 14. Acids have a low pH, taste sour like lemons, or oranges, and will turn the paper red. As materials become more basic, the color of the paper changes from green to yellow to various shades of blue. Bases have a higher pH, are “slippery”, and will turn the paper blue or purple. You are going to be given four different liquids and will use the pH paper to determine which liquids are more acidic, basic, or neutral.



In the center of the table are four small cups labeled 1, 2, 3, and 4 each containing a little bit of four different liquids and covered with a 3x5” index card divided into 6 sections In front of each student are four small strips of universal indicator paper, 4 Q-Tips and a paper towel. Each student should lay their paper towel down longways and place their four pieces of indicator paper on it. Student No. 1 should begin the process by carefully dipping his/her first Q-Tip into


24

The Program-Experiment 3: Indicators of Different Types

Presenter’s Guide the liquid in cup 1 and touching it to one end of his/her first piece of indicator paper. Students 2-

5 should repeat these steps using cup 1 and one of their Q-Tips. The students should put their first Q-Tips inside the cup when all have used that liquid. Repeat this process for each of the remaining 3 cups using a new Q-Tip and a new piece of indicator paper each time. The students should place their indicator papers in front of them in order on the table.

Look at what colors the papers turn. Taking turns, each student should compare his/her pH paper color with the color scale in the center of the table. They should use their pencil to record the pH next to the pH paper in front of them (or on it if there is a dry spot). Have student number 1 complete the index card for solution 1, asking each student in turn their resulting pH and recording it on the card. Have student number 2 complete the index card for solution 2, asking each student in turn their resulting pH and recording it on the card. Repeat with students 3 and 4 using solutions 3 and 4. Student 5 should then collect all the cards and average the results, placing the answer in the last blank space and circling the answer.

Conclusions

Tell the students :

Based upon the color of the indicator paper seen for the liquid in each cup, what is the pH of the liquid in each cup? Ask Student 5 to give the average pH for each cup. Is your liquid more acidic, basic, or closer to a neutral pH of 7?

Cup 1 = Vinegar with a pH of 3. The paper should be reddish orange.

Cup 2 = Water with a pH of 6-7. The paper should be yellowish green.

Cup 3 = Baking Soda with a pH of 8. The paper should be green.

Cup 4 = 0.1 M Borax with a pH of 9. The paper should be darker green.

Technical Information (for the Demonstrator): pH is a numeric scale used to quantify the acidity, or basicity of a material. pH is the negative log of the hydrogen ion concentration in a solution. The greater the concentration of hydrogen ions, the more acidic a solution is. The pH scale ranges from 1 to 14. 1 is more acidic and 14 is more basic. A pH of 7 is neutral. pH, or Litmus Paper changes color when exposed to acids and bases. The paper contains a universal indicator that exhibits a gradual color change across the pH scale. Indicators are usually made from natural substances called anthocyanins, which can be found in cabbage juice, flower petals, berries, or fruits. pH paper is soaked in a universal indicator and then dried.


25

The Program-Experiment 4: Appearing Ink





Disappearing ink of one sort or another has been used by spies to create hidden messages for centuries. In Washington’s time the “ink” usually consisted of a mixture of ferrous sulfate and water, and the message was hidden between lines of visible ink. The recipient placed the paper over the flame of a candle or treated it with sodium carbonate which would to form a colored precipitate iron (II) carbonate to reveal the letter’s hidden contents.

We’re going to “develop” our secret message (already written on index cards with phenolphthalein) with a basic solution so the ink will be appearing in our case—not disappearing. If the students work together they’ll be able to “read” the secret message: N C W

20 15.


Tell the Students:

Color in chemistry is very important. Chemists are needed to make stable colors for food, paints, dyes, inks; they use color to tell if reactions have occurred, if temperatures have changed, to diagnose illnesses, to analyze what’s in things and to tell what the properties of things are. A fun use of color in chemistry is to make hidden messages appear.

Have you ever heard stories of George Washington’s spies? At the time of the Revolutionary

War spies wrote messages using invisible ink. A hidden message was written between the lines of a normal message and could only be deciphered if one knew it was there and how to

“develop” it. Washington’s spies knew exactly what they were doing. The receiver of the message could brush the letter with another chemical to reveal the secret message.

Today we’re going to use a similar technique to decipher a message hidden on index cards in a more colorful way.



Each student has the following at his/her place:

1.

A 3”x5” index card which has parts of a secret message on it.

2.

A Q-tip.

3.

A small cup marked B containing a basic solution.


26

The Program-Experiment 4: Appearing Ink


Ask each student to dip their Q-tip in the basic solution (don’t make them too wet!) and paint the index card with it. A message will appear on each card. Ask the students what the message is.

( Ans : taken together the message, which is spread out among the 5 cards at each table, is “N”

“C” “W” “20”, “15”.)

Conclusions

Ask/Tell the students the following:

Ask the students at each table if any table can tell you what the secret message is. ( Ans :

NCW2015). The students at each table will have to co-operate and work together to come up with it.

The messages that the students retrieved were a little more colorful than the ones decoded by

Washington’s spies. We had fun with ours, but the use of hidden messages was a key element in helping George Washington win the Revolutionary War.

Additional Information If Needed: Technical Background

For more on George Washington’s spies, see http://www.mountvernon.org/georgewashington/the-revolutionary-war/spying-and-espionage/spy-techniques-of-the-revolutionarywar/ .


27

The Program: Experiment 5 Patriotic Colors





Using chemistry we’re going to create three different colors—red, white and two blues. The first will be a red-brown colored complex of Fe(SCN)

2

+, the second will be CaCO

3 while the last will be Cu complexed with NH

4

+ and monoethanol amine (MEA).



Let’s talk about pigments like the cave men used. Pigments are used for paint. If you’ve painted your bedroom or part of your house you know that paint is colorful and long-lasting. Paint chemists have done amazing things with paint. They can make it insulating, reflective, camouflaging, glow-in-the-dark, mildew-free, self-healing when it gets scratched, they can make chalkboard or white board paint, and just about any color under the sun (or rather in the sun



).

Paint chemists do all kinds of interesting things. They can experiment with the size of pigment particles. Gold is actually pink at nano particle size. TiO

2

, which is brilliant white, can be miniaturized or micronized, and made invisible and used in sunscreens. Chemists experiment with particle sizes, fillers, binders, and all the things that make up paint. Being a paint chemist is interesting and fun.

What is in all this fancy paint?? We actually still use iron oxides like the cave men used. And natural minerals like TiO

2

for white paint. We also can make synthetic paint. Today we will make some paint. What color would you like to make? What 3 colors did early Americans choose to represent our country in our flag?

In this experiment we’re going to see how chemistry can be used to synthesize pigments and to create the colors of our flag: red, white and blue. In fact we’re going to make red, white and two shades of blue. When these colors have all been created, we’re going to compare them to paint chips from Cleveland’s own Sherwin-Williams company—one of the first paint companies in the world.


Tell the students to do the following, allocating tasks among all the students at the table:

Color No. 1:

At center of each table have the students locate the following:


28



1.

1 50 ml vial marked 8 (contains 10 ml of 0.1M KSCN solution).

2.

1 10 ml vial marked 9 (contains 10 ml of 0.1M FeCl

3 solution).

3.

1 4 ml beral pipette.

4.

1 wooden stirrer.

Ask one student to carefully open the 50 ml vial marked 8. Ask another student to open the 10 ml vial marked 9, and ask a third student to take one of the pipettes. (You might want to go in order: ask Students Nos. 1, 2 & 3 to perform this part of the experiment. The other two students can observe Color No. 1 but then should be the first to perform Color No. 2, etc.)

Ask the student with the pipette to fill it (~3ml) with the solution in the 10 ml vial marked 9 and then empty it into the 50 ml vial marked 8. Ask the student with the 50 ml vial to gently stir the mixture in his/her vial with a wooden stirring stick. What’s happening? ( Ans : the solution in the

50 ml vial should have turned red.)

Now ask the students to repeat these steps, stirring with the same wooden stirrer after addition, until the solution in the 10 ml vial has been exhausted. The student with the 50 ml vial should re-cap it tightly (until the cap clicks). At the end this process the solution in the 50 ml vial should be a blood-red Fe complex.

Color No. 2


1.

1 50 ml vial marked 10 (contains 10 ml of 1M aqueous CaCl

2 solution).

2.

1 10 ml vial marked 11 (contains 10 ml of 1M aqueous NaHCO

3 solution).

3.

1 4 ml beral pipette.

4.

1 wooden stirrer.

At each table ask one student to take the 50 ml vial marked 10, another to take the 10 ml marked

11 and a third student to take a pipette. Ask the students with the vials to carefully open them.

Ask the student with the pipette to fill it (~3ml) with the solution in the 10 ml vial marked 11 and then empty it into the 50 ml vial marked 10. Ask the student with the 50 ml vial to gently stir the mixture in his/her vial with the new stirrer. What’s happening? ( Ans : the solution in the 50 ml vial should have turned white.) When finished stirring, put the cap back on tightly (until it clicks).

Color(s) No. 3


1.

2 50-ml vials marked 5 (contains 10 ml of 2% CuSO

4).

2.

1 10-ml vial marked 6 (contains 5ml of household NH

4

OH.)

3.

1 10-ml vial marked 7 (contains 10ml of 10% monoethanol amine, MEA.)


29



4.

2 4 ml beral pipettes.

5.

2 wooden stirrers

Ask one of the students to carefully open one of the vials marked 5. Using one of the small pipettes provided, ask a second student to add 10 drops of the solution from the 10 ml vial marked 6 into the first 50 ml vial marked 5. Tell the first student gently stir the vial marked 5 with another new wooden stirrer. What happened? ( Ans : The solution turns deeper blue color--

Cu(OH)

2

formation, temporarily.) When finished stirring, put the cap back on tightly (until it clicks).

Now tell the students to remove the cap from the first 50 ml vial marked 5 and slowly and carefully pour all of the contents of the 10 ml vial marked 6 into the first 50 ml vial marked 5.

Put the cap back on the 5 vial and gently stir again with the same stirrer. What happened this time? ( Ans : The copper has formed a different complex. This complex absorbs all the colors of the rainbow except the blue light, which is what we see as a deep dark blue.) When finished stirring, put the cap back on tightly (until it clicks).

Now set the first vial marked 5 aside and open the other vial also marked 5.

Using different students and a clean pipette, add 5 2 ml portions of the solution in the 10 ml vial marked 7 Carefully stir the 50 ml vial after addition with last new stirrer. What’s happening this time? (Ans: Solution gets slightly darker as each aliquot is added. At the end it should a deep bluish-purple.) When finished stirring, put the cap back on tightly (until it clicks).

Conclusions


Now ask the students to compare the final colors in each of their 50 ml vials with the paint chips from Sherwin Williams. It’s best if they hold the 50 ml vials horizontally and view their contents from the side while holding the paint chips behind the vial. See if you can get a consensus for which S-W colors most closely match all four colors.


The red precipitate is an intense red-brown colored complex of Fe(SCN)

2+

according to the stoichiometry Fe

3+

(aq) + SCN

− (aq) ↔ [Fe(SCN)] 2+

(aq).

The white precipitate is just CaCO

3

—this material is chemically similar to Plaster of Paris.

The blue colors are copper complexed with NH

4

+ and monoethanol amine (MEA).


30

The Program: Experiment 6 Many Colors from One





In this experiment we’re going to use paper chromatography to separate a mixture of food colors into its four components: red, yellow, blue and green. For comparison we’re going to test a single food color to demonstrate that a single color does indeed “separate” into a single ring of color.



We learned about paint pigments and all the colors that can be made. What happens when we mix pigments? Yellow and blue make….?” “Red and blue make…?” Paint chemists mix a lot of really cool colors together to get their colors. In the paint chip Fusion, which is lime green, there are many colors: there's white TiO

2

and yellow in the base paint. Then there is black, blue, and yellow added in.

What if we mix equal amount of red, yellow, and blue? We will get black. We are going to do a “reverse experiment” to show something interesting.



Part 1

We’re going to use a technique that chemists everywhere use to separate colors that have been mixed together.

In front of each student are two round pieces of (filter) paper, two square pieces of waxed paper and a paper towel. Each student should lay the two pieces of waxed paper down in front of them, side by side, and place one of the pieces of round paper on each of them.

In the center of the table are two 10ml vials, one marked either B, G or Y and a second marked

M. Each of these vials contains food dyes which might color their hands or clothes if spilled, so please ask them to use care. Ask one student to take the vial marked either B, G or Y, open it and then get a tiny amount of the dye in one of the clean pipettes. Put a single drop of dye in the center of the first piece of filter paper and then squirt the remainder of the dye back into the vial.

Pass the vial and the pipette to the second student who repeats these steps. After putting a single drop of dye on the paper, the students should dry it somewhat by blowing on it or waving it in the air.


31

The Program: Experiment 6 Many Colors from One


Now repeat all of these steps with the same vial putting a second drop directly on top of the first one. After each of the student’s second dye drops have had a chance to dry a bit, they should now pick up a second clean pipette. Ask the first student to take the cup marked W in the center of the table, get some water into the second pipette and put 4 drops of water right over the drop of dye. Pass the cup of water and the pipette to the next person. Leave the pipette in the water cup to use later.

Now repeat the entire process at each table using the second piece of filter paper and the dye in

10ml vial marked M, using the third clean pipette and letting the paper dry between drops.

When the second drop has dried, use the cup of water with the water pipette and add 4 drops right over the drop of dye marked M. When all steps have been completed, the students should lay their filter papers down side by side.

Tell the students that they can take the dried filter papers home with them.

Demonstrator: Return to Part 2 of Experiment 1 and then Part 2 of Experiment 2 and complete these parts.

Part 2

Conclusions


Look at the two pieces of round piece of paper which had the dots in the center. What’s happened? ( Ans : the dye from the vial marked either B, G or Y has formed a single ring of color.

The dye from the vial marked M has separated into three rings: yellow, blue and green with a red blotch in the center. Those must be the colors that were combined together to make the black mixture.

Now we know what colors can be combined together to make black!

Demonstrator: Complete Part 3 of Experiment 1 before concluding.


32

Closing Session


Closing Session

•

Remind the students that we need their help to determine which experiment they liked the most. So vote for your favorite experiment AND the experiment that helped you learn some fun facts about the chemistry of colors. Use your golf pencil to complete your Student Feedback form now.

•

Distribute copies of Celebrating Chemistry 2015 . Leave any extra copies with the librarian.

•

Tell them to click on Contests!

on the Cleveland Section’s web site (Google Cleveland

National Chemistry Week ) for information on how to enter our Chemistry and Poster Contests where each student receives a small token for entering and can win local and national cash prizes.

•

Tell the students that you hope they enjoyed our adventures with colors and you hope that they’ve learned a lot.

•

Before dismissing the students , ask the librarians and helpers to dispose of any excess

Rit dye and fluorescent dye—over newspapers in your large trash bag . These dyes may stain ceramics, so don’t dispose of them in the restroom facilities. Deposit all other liquids into your bucket and then place all other items (with the exception of the pencils and pH scales) in the trash bag.

•

Thank the students and parents for coming to this year’s demonstration and learning about the chemistry of color. Remind them to take home their chalk, dyed fabric, filter paper and their part of the secret message home with them.

•

Have the students come to the closing area to turn in their goggles and Student Feedback forms. Have them put their goggles back into the box and then give it to the librarian for return to Julia Boxler at the main library.


33

Clean-up & Return Procedures


Cleanup & Return Procedures

A.

General clean up procedures for experiments

•

All solid waste other than the chemicals can be placed into a regular trash bag.

•

Any liquid wastes other than the Rit and fluorescent dye should be disposed of into sinks, toilets or the bucket that you brought.

•

To dispose of all the Rit and fluorescent dyes , put newspapers in the trash bag and pour any and all solutions onto the newspapers in the trash bags.

•

Check with the librarian if they are willing to take the trash; otherwise, please dispose of it with your own trash.

B.

Returns

•

Other than goggles and Feedback and Photo Permission forms, the only items we’d liked returned from this year’s library program are the golf pencils and the pH scales.

•

The students can take their chalk, their dyed fabric, filter papers and secret message home with them.

•

Please complete the hardcopy Demonstrator Feedback form this year and return it in the manila envelope address to Julia Boxler.

•

Place the completed Demonstrator and Student Feedback forms, the signed ACS Photo

Permission forms with a description of the photo to which it belongs and the golf pencils and pH scales (in a dry plastic bag please) into the manila envelope labeled “Julia Boxler

YTH ”.

C.

Goggles:

•

If you are performing another demonstration for this year’s National Chemistry Week, sanitize the goggles between demonstrations with a dilute bleach solution as instructed in the written directions found on the underside of the cover of the goggle container. Be sure to dry them with soft cloth or soft paper towels to prevent scratching. Please stack them into their box without twisting or crushing!

•

If you are finished performing your demonstration(s) for this year, place the used goggles into their box and give the box to the librarian for return to us through the Library system.

Please stack them without twisting or crushing! There is no need to clean them when you are through; our Planning Committee will clean and sanitize them for the next year and/or for other programs.

D.

Before you leave the library

•

Return any items borrowed from the library.

•

Give any leftover literature to the librarian. (You may save a copy for yourself though!)


34

Clean-up & Return Procedures


•

Give the manila envelope (containing completed forms, pH scales and pencils) as well as the box of goggles to the Children’s librarian with instructions to put it them in the interlibrary mail. (Or take to your nearest CCPL library branch.)

At Home (Feedback)

•

If you took any photos to share (and have submitted signed permission forms to us), please email them to Bob Fowler at jrfowler@cox.net

. Please note that any photos that you care to share with us could end up on our web site and/or possibly with ACS if we choose to use your photo in one of award self-nominations.

•

Smile!

You may have expanded or even sparked scientific interest in a student today!

☺

☺ ☺ ☺ ☺ ☺

THANK YOU!

… for your participation in our program this year.

We hope you will join us next year too. Planning of experiments and contests starts in April.

You don’t have to be a teacher or scientist to join our Planning Committee; all you need is a desire to share science with students. Development of ideas and refinement of experiments goes on throughout the summer (a couple of hours every other week), donation gathering and shopping is in late summer, and kit assembly (about 50 of them needing a lot of volunteer hands) is on a Saturday in mid-September. It takes many, many volunteers to develop and put on all our programs. Even a little bit of help goes a long way. Please contact us this year or next at jrfowler@cox.net

if you (or a friend of yours) want to join in on the activities!


35

Appendices


Appendices

A. Material Safety Data Sheets

Most MSDS’s (now called SDS’s—safety data sheets) can be found at http://www.flinnsci.com/msds-search.aspx

.

B. Supply list for recreating these experiments

Material resources for reproducing the experiments for items not found in your local grocery/drug/hardware store:

•

The multi-fiber ribbon was ordered from Educational Innovations at http://www.teachersource.com/product/multi-fiber-ribbon/forensic .

•

Food coloring can be purchased in bulk at Amazon.

•

2"x3" plastic bags and cardboard boxes may be purchased at Uline

( http://www.uline.com/index.aspx?pricode=WE412&AdKeyword=uline&AdMatchtype= e&gclid=CP7mqI6P0scCFZJgfgod7roONQ&gclsrc=aw.ds

).

•

Chemical reagents can be purchased from Flinn Scientific ( http://www.flinnsci.com/ ).

Caution: Flinn will only ship to academic, professional and similar institutions.

•

Fluorescent pigments/dyes were obtained from the Day-Glo Corporation

( http://www.dayglo.com/ ).

•

Paint chips were obtained from the Sherwin-Williams Corporation ( http://www.sherwinwilliams.com/homeowners/specialoffers/?WT.srch=1&WT.mc_id=OPT%20PPC%20DIY&mkwid=sW8BkA2ns_dc&pcrid

=84727766938&pkw=sherwinwilliams&pmt=e&gclid=CKHT3qGQ0scCFcRlfgodq0gIVw ).


36

Addendum on Color Theory, Pigments and Dyes


Addendum on Color Theory, Pigments and Dyes

The information in this section is from several sources including http://www.4college.co.uk/a/Cd/fabric.php

.

Here’s some information about the Theory of Color and how our eyes see color that might be useful:

A primary color of light is a color that cannot be made from a combination of any other colors, typically red, blue and green. A secondary color is a color created from a combination of two primary colors. Tertiary color is a combination of three colors (primary or secondary).

Additive color synthesis is the creation of color by mixing colors of light (NOT pigments) .

Human vision relies on light sensitive cells in the retina of the eye. There are two basic kinds of sensors. These are rods and cones. Rods are cells which can work at very low intensity, but cannot resolve sharp images or color. Cones are cells that can resolve sharp images and color, but require much higher light levels to work. The combined information from these sensors is sent to the brain and enables us to see.

The sun has all the colors, and a prism will break them apart. And you can combine different colors of light and get white in return. Spin the color wheel. This is a property of spectral colors

(wavelength of light). With pigments, black can be like the sun, with all its colors. And chromatography is like a prism, splitting all the components apart.

There are three types of cones. Red cones are sensitive to red light, green cones are sensitive to green light, and blue cones are sensitive to blue light. The perception of color depends on an imbalance between the stimulation level of the different cell types.

Additive color processes, such as television, work by having the capability to generate an image composed of red, green, and blue light. Since the intensity information for each of the three colors is preserved, the image color is preserved as well. The spectral distribution of the image will probably be wrong, but if the degree of intensity for each of the primary colors is correct, the image will appear to be the right color.

The three primary colors in light are red, blue, and green , because they correspond to the red, green, and blue cones in the eye. When red, green and blue light are mixed, white light results.

Mixing of the primary colors produces secondary colors: Red + Green = Yellow, Red + Blue =

Magenta & Green + Blue = Cyan.

Subtractive color synthesis is the creation of color by mixing colors of pigment, such as paint or ink in your computer’s printer. This type of color is what is used in the art and design world.

When learning basic color theory, art students typically use familiar colors like red, yellow, and blue.


37



Subtractive color processes work by blocking out parts of the spectrum. The idea of subtractive color is to reduce the amount of undesired color reaching the eye. If, for example, you had a yellow image, you would want to have a dye that would let red and green reach the eye, and block out blue. The additive secondaries become the printers’ subtractive primaries, because each of the additive secondaries will reflect two of the additive primaries, and absorb one of the additive primaries.

The three primaries on the artists’ color wheel are red, blue, and yellow . When all of these colors are combined, they create black pigment.

Colors come from a variety of sources. Turnsole became a mainstay of medieval manuscript illuminators starting with the development of the technique for extracting it in the thirteenth century,[1] when it joined the vegetable-based woad and indigo in the illuminator's repertory.

However, the queen of blue colorants was always the expensive lapis lazuli or its substitute azurite, ground to the finest powders. According to its method of preparation, turnsole produced a range of translucent colors from blue, through purple to red, according to its reaction to the acidity or alkalinity of its environment, in the chemical reaction, not understood in the Middle

Ages, that is most familiar in the Litmus test.

A note on white: In Tom Sawyer’s day, whitewash was probably white chalk (limestone) mixed with water. Many colored paints were pigments mixed with milk…which took some skill and effort to use, and you had to work quickly! Today’s chemists can make white paint whiter than white by adding optical brighteners that absorb UV light and release it as visible light. So you see this light, plus the normal reflected white.

Folium ("leaf"), was actually derived from the three-lobed fruit), not the leaves. In the early fifteenth century, Cennino Cennini, in his Libro dell' Arte gives a recipe "LXVIII: How you should tint paper turnsole color" and "LXXVI to paint a purple or turnsole drapery in fresco."

Textiles soaked in the dye vat would be left in a close damp cellar in an atmosphere produced by pans of urine. It was not realized that the oxidizing urine was producing ammonia, but the technique reminds us how foul-smelling was the dyer's art.

The colorant was downgraded to a shading glaze and fell out of use in the illuminator's palette by the turn of the seventeenth century, with the easier availability of less fugitive mineral-derived blue pigments.

Turnsole was used as a food colorant, mentioned in Du Fait de Cuisine which suggests steeping it in milk. The French Cook by François Pierre La Varenne (London 1653) mentions turnsole grated in water with a little powder of Iris.

Herbals indicated that the plant grows on sunny, well-drained Mediterranean slopes and called it solsequium ("sun-follower") from its habit of turning its flowers to face the sun; alternatively it might be called "Greater Verucaria";[2] early botanical works gave it synonyms of Morella,

Heliotropium tricoccum and Croton tinctorium .


38



Acidic Dyes:

This group include Kool-Aid and most food dyes, especially reds. The “acid” in “acid dyes” refers not to the dyes themselves, but to the environment they bind in. For Kool-Aid , the acid is already present in the mix (in the form of citric acid crystals), for other dyes, it’s added as vinegar (which is acetic acid) or sometimes citric acid. Acid dyes are anionic (south pole) dyes, which use heat and an acidic environment to form ionic bonds with fiber. These contain acid groups, such as –COOH and –SO3H which form attractions to the slightly basic –NH groups in the amide links of wool, silk and nylon.

Direct Dyes:

Dyes in this category are Cushings Direct Dyes, Jacquard iDye Direct Dyes, ProChem’s Diazol

Direct Dyes and any “universal” dye like RIT. These bond to fabrics by hydrogen bonding and so are particularly attracted to cellulose fibers, such as cotton and rayon, which have many –OH groups.

Reactive dyes:

Dyes in this category are Procion MX, Dylon Cold, Lanaset/Sabraset, Cibacron F, Prochem

Sabracron F, Remazol and Vinyl Sulfone. In a reactive dye a chromophore contains a substituent that reacts with the substrate. Reactive dyes are most commonly used in dyeing of cellulose like cotton or flax, but also wool is dyeable with reactive dyes. Reactive dyeing is the most important method for the coloration of cellulosic fibers. Reactive dyes can also be applied on wool and nylon; in the latter case they are applied under weakly acidic conditions.


39

Paint Your Town Beautiful…with Chemistry National Chemistry Week Planning Committee Cleveland Section

Prepared by the

National Chemistry Week Planning Committee

of the

American Chemical Society

Cleveland Section

for

National Chemistry Week 2015

Paint Your Town Beautiful…with Chemistry

Table of Contents Page

List of Experiments

How Experiment Write-ups are Organized

Presentation Overview

VOLUNTEERS

MAKE SURE TO FOLLOW ALL DIRECTIONS IN EXPERIMENTS

Websites of Interest

Check Lists

Supplies for Demonstrator to Bring from Home

Supplies for Demonstrator to Bring from Home

Supplies Included in Your Kit

Supplies Included in Your Kit

Experimental Setup

Experimental Setup

Experimental Setup

Experimental Setup

Experimental Setup

Greeting the Students and Opening Discussion

Greet the Students (and Parents) Upon Their Arrival, Distribute

Goggles, and Organize the Seating

Opening Discussion

Background for the Demonstrator (only)

Background for the Demonstrator (only)

Road Map of Experiments

Road Map of Experiments

1.

Complete Part 1 of Experiment 1 [ Glowing Chalk ] (down to the point where the plaster is poured into the molds).

2.

Complete Part 1 of Experiment 2 [ Which Fabrics Turn Color?

] (down to the point where the fabrics are put into cups of dyes to soak.)

3.

Complete Experiment 3 [ Indicators of Different Types].

4.

Complete Experiment 4 [ Appearing Ink]

5.

Complete Experiment 5 [ Patriotic colors] .

6.

Complete Part 1 of Experiment 6 [ Many Colors from One] (down to the point all the filter papers have been impregnated with the dyes.)

7.

Complete Part 2 of Experiment 1 (remove paper cocoon and allow chalk to absorb light).

8.

Complete Part 2 of Experiment 2 (remove fabric samples from dyeing solutions & examine results of staining processes).

9.

Complete Part 2 of Experiment 6 (examine chromatographic results).

10.

Complete Part 3 of Experiment 1 (demonstrate how chalk glows in the dark).

Introduction for the Students

Introduction for the Students

Experiment 1: Glowing Chalk (Individual Experiment)

Experiment 2: Which Fabrics Turn Color? (Demonstration/Group

Experiment)

Experiment 3: Indicators of Different Types (Individual

Experiment)

Experiment 4: Appearing Ink (Individual Experiment)

Experiment 5: Patriotic Colors (Group Experiment)

Experiment 6: Many Colors from One (Individual Experiment)

Closing Session

Cleanup & Return Procedures

THANK YOU!

Appendices

Addendum on Color Theory, Pigments and Dyes

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