Name: _______________________
Period: _________
Date: ________
Mystery Mixture
!
!
Background:
There are millions of different substances in the world. For the next few weeks we will be
investigating the properties and composition of a few of them . The study of substances and their
interactions is chemistry. At the start of this lab, you are going to be given a white powder, of unknown
composition, unknown to you and me. We only know that it is a safe mixture of two substances. Your
task is to analyze and identify what the two substances are.
The foundation of scientific investigation is careful, precise observation. Methodically observe
all aspects of the substance. Go slowly. Take your time. Do not rush to complete the steps. Rushing
causes you to miss the small details that often make the biggest difference.
Question:
What two substances make up the mystery mixture? How do you identify a substance?
Materials:
5 mL of mystery mixture
1 plastic cup, 250 mL
2 pipettes
2 hand lenses
1 cup of water
Protective eyewear
Part One: Observe
1.
2.
3.
4.
Place 5 mL of mystery mixture in the plastic cup.
Carefully observe the mixture. Do not touch or taste.
Record your observations.
Compare and discuss your observations with another group.
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Part Two: Add water
1.
2.
3.
4.
5.
Add one pipette of water to the mystery mixture. Do not use the pipette to stir the mixture.
Observe.
Take turns adding additional pipettes of water, pausing to observe as you go.
Record your observations.
Compare and discuss your observations with another group.
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Discussion and Conclusions:
Name: _______________________
Period: _________
Date: ________
White Substance Information
!
!
Background:
A substance is a form of matter. There are millions of different substances on Earth, each
different from every other substance. Each of the vials you will use in this lab contains a different pure
substance…no mixtures. Observe and become familiar with each substance, their names, and their
properties. Two of these substances make up the mystery mixture. Your task is to identify which of
these substances are form the mystery mixture.
The label has three ways to identify each substance. The top line is the chemical name. The
second line (in parentheses) is the common name for the substance. The third line is the chemical
formula. Chemical formulas are used to easily identify the elements and the proportions of those
elements used in making a compound. Chemical formulas will be taught in great detail later.
Calcium carbonate
(chalk)
CaCO3
Chemical name
(common name)
Chemical Formula
You will need to use the information sheets provided to you, as well as your laboratory investigations,
to complete the following table. As mentioned in earlier labs, careful and patient observations pay off.
Chemical
Name
Chemical
Formula
Common
Name
Observations before water
1
2
Uses
Observations after water
3
4
5
6
7
8
9
Look for patterns in the chemical formulas and chemical names of the substances. What patterns do
you see? Can you read the chemical formula based on these patterns?
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Notes:
Summary Questions:
1. Which substances do you think might be in the mystery mixture?
2. What evidence do you have to support these hypotheses?
3. What additional evidence would help you to prove your hypothesis?
Name: _______________________
Period: _________
Date: ________
Two Substance Reactions
!
!
Background:
A substance is material with specific physical and chemical properties. Physical properties
include such things as taste, smell, color, shape, luster, melting point, boiling point, etc. Chemical
properties have to do with what happens when you mix that substance with other substances. For
instance, when you mix oil and water they remain separated. That same oil and water should always
separate when mixed…that is one of their properties.
A mixture is a combination of substances that are physically combined. They do not create a new
substance and still have the same individual properties they had before you mixed them together.
Consider a mixture to be like a fruit salad. You put a bunch of different types of fruit in and, when you
take a bite, you taste all the different fruits, not something totally different.
Do not rush!!! Mix two substances in a well, test, and record your observations. Then, test a
separate hypothesis. You should be able to, at any time, identify which substances were being tested in
which well.
Question:
Which two substances make up the mystery mixture?
Materials:
1 Set of nine white
10
1 Vial of mystery mixture
2

substances
2 Dropper bottles of water
Minispoons, green
Well trays
Protective eyewear
Procedure
a.
Put one level minispoon of two different substances (or two minispoons of ONE
substance) in a well. It is
important you record the number of the well you are
observing.
b.
Add 10 drops of water.
Well
Number
Substance
1
Observe and record.
Substance
2
Results
1
2
3
4
5
6
7
8
9
10
11
12
Notes:
+
+
+
+
+
+
+
+
+
+
+
+
Summary Questions:
1. Which two substances do you think make up the mystery mixture? Please list your evidence. This
should be very helpful in completing your CTQs.
2. When you added water to the mystery mixture (and other mixtures), bubbles were produced. What
are bubbles?
3. Where did the bubbles come from?
Discussion:
(view evaporation tests on FOSSWeb at this point!!)
What is a chemical reaction? How do you know a chemical reaction has occurred? How is this different
than two mixed substances?
Critical Thinking Questions (CTQs)
At this point, you have done two separate labs and some research into the identity of the mystery
mixture. You are now ready for your first set of Chemistry CTQs. These are the same as those for the PS
labs, but with one catch. You are now not using the data from one investigation, but a series of three
small investigations (mystery mixture, white powder research, and two substance reactions) to make
ONE CLAIM about the identity of the mystery mixture. It will require using data from ALL THREE
INVESTIGATIONS to make your claim. We will allow some time in class for you to compare
observations with other groups, repeat and confirm your data (if necessary), and create claims you are
confident are correct.
Name: _______________________
Period: _________
Date: ________
Reaction in a Bag
!
!
Background:
A chemical reaction is when the interaction of two or more substances creates one or more new
substances. In the mystery mixture labs, you combined two substances, added water (a third
substance) and the result was, among other things, the creation of a gas. Since you put a liquid and two
powders in the well, this substance (with new properties) had to have been a new substance. The
substances you put into the well are referred to as the reactants, the starting substances. The resulting
substances after a reaction takes place are called the products. Today you will be observing the
physical properties of the reactants and the products.
Question:
What kinds of changes might be indicators of a chemical reaction?
Materials:
30g
30g
1
Calcium chloride (CaCl2)
Water
Plastic bag
30g
2-5
mL

Sodium Bicarbonate
(NaHCO3)
Bromothymol Blue (BTB)
Protective eyewear and
aprons
Procedure:
1. Observe the physical properties of each of the reactants (the starting substances). Record
your observations in table 1-1.
2. Mass each of the substances and record the mass in table 1-1. Mass of the bag:
TABLE 1-1: PHYSICAL PROPERTIES OF REACTANTS
Substance
CaCl2
NaHCO3
H20
BTB
Physical
Properties
TOTAL MASS
OF
REACTANTS
Mass of
Substance
3. Predict what will happen when we combine all the ingredients in the bag. Write your prediction
here.
4. Pour 30 grams of Calcium chloride in the plastic bag.
5. Pour 30 grams of Sodium bicarbonate into the plastic bag. Seal and mix thoroughly.
6. Add the BTB to the water (in a beaker). Stir.
!
At this point, the last few steps will happen very quickly. Read the steps five through eight
completely before moving on so you can do it all at once.
7. Pour the water/BTB mixture into the bag. Seal quickly and completely. Shake continuously to mix
the ingredients while the reaction is occurring.
8. Observe the reaction and record your observations. Remember to be thorough.
Observations during the chemical reaction:
9. Observe and record the physical properties of the products of the reaction.
TABLE 1-2: PHYSICAL PROPERTIES OF PRODUCTS
Physical Properties of the Products
10. Mass the bag and the products (substances produced in the reaction). Record the mass of your
products in table 1-3.
Mass of the bag and the
products
Mass of the bag (from step 2)
MASS OF PRODUCTS
11. Compare your observations to those of other groups.
12. Don’t forget to clean up (using plenty of cleaner, not just towels).
Summary Questions:
1. How did the mass of your products (the end substances) compare to the mass of your reactants
(the starting substances)?
2. Justify/Explain possible reasons for this comparison of the starting and ending masses.
Discussion and Notes:
(Products and reactants, and energy in a chemical reaction will be discussed)
Level II ideas:
1. Recreate this investigation with a different amount of one substance and compare the results to this
investigation. For instance, how does the presence of more sodium bicarbonate affect the outcome?
Name: _______________________
Period: _________
Date: ________
Mystery Mixture Elements
Part 1. Identifying elements
Substance
Chemical
Formula
Calcium carbonate
CaC03
Sodium carbonate
Na2CO3
Sodium
bicarbonate
Elements
NaHCO3
Magnesium sulfate
MgSO4
Calcium chloride
CaCl2
Sodium chloride
NaCl
Ascorbic acid
C6H8O6
Citric acid
C6H8O7
Sucrose
C12H22O11
Part 2. Questions
1. Which substance has the greatest number of elements? _____________ How many?
__________
2.
Altogether, how many different elements are in the nine substances?
__________________
3. Which element is found in the greatest number of substances?
________________________
4. How many elements are in the substance carbon dioxide?
____________________________
5. How many elements are in the substance water?
________________________________________
6. Which of the nine substances are made of two elements?
_________________________________
_____________________________________________________________________________
____
7. Which of the nine substances are made of three elements?
________________________________
_____________________________________________________________________________
____
8. Which of the nine substances are made of four elements?
________________________________
_____________________________________________________________________________
___
Name: _______________________
Period: _________
“Elements” Questions
1.
What is an element?
Date: ________
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_
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_
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_
2. How are matter and elements related?
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_
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_
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_
3. How was Mendeleyev able to predict the existence of elements that had not yet been discovered?
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_
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_
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_
4. What is the periodic table of elements?
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_
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_
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_
Discussion and Notes:
Name: _______________________
Period: _________
Date: ________
Elements in Products
Part 1. List the elements found in several products.
Product Name
Elements
Part 2. Analyze the elements in the products.
1. How many different elements did you find in the all the products you investigated?
__________________________________________________________________________________________________________
2. What is the most common element in the products you investigated?
__________________________________________________________________________________________________________
3. How many metals did you find in the products you investigated? List them.
__________________________________________________________________________________________________________
Name: _______________________
Period: _________
The Periodic Table
Date: ________
Name: _______________________
Period: _________
Date: ________
The 50 Most Common Elements
The Periodic Table of Elements is a way of displaying the fundamental substances called elements.
Each box has a different element. As you can see, there are over 100 elements. Only the first 90 or so
are naturally occurring. The rest are created only in labs. Elements are the basic building blocks of
matter. Everything on Earth that has mass and takes up space is made of elements. All substances are
made of elements. Notice that all elements have a specific symbol and atomic number.
During this chemistry unit, you are going to be asked to memorize the name, symbol, and atomic
number of the 50 elements highlighted below. They are the most common 50 elements on Earth. The
purpose is to make you familiar with them as you will be dealing with them throughout high school and
years after.
Many students have found it helpful to highlight the elements in groups of 10 so they remember
which elements are tested together. Some have also found it helpful to create flashcards or use quizzes
on websites like FOSSWeb and Freerice.com
Name: _______________________
Period: _________
Date: ________
Response Sheet - Elements
Carla studied the ingredients on a box of cereal.
found.
She made a list of the elements she
She told her friend,
This cereal contains eight different elements.
the rest of the cereal is made of.
If you were Carla’s friend, what would you tell her?
I wonder what
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Notes:
Name: _______________________
Period: _________
Date: ________
“Elements in the Universe” Questions
1.
What element is among the five most abundant elements in the Sun, Earth, ocean,
atmosphere, and organisms?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
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___________
2.
What does it mean when people say that everything is made of stardust?
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___________
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___________
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___________
3.
Why are the elements carbon, hydrogen, oxygen, and nitrogen important to life on
Earth?
_____________________________________________________________________________
___________
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___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
4.
How can there be so many different substances in the world if there are only a few
elements that are common?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
Name: _______________________
!
Period: _________
Date: ________
How Much Gas? Part A
Background:
In earlier investigations, you observed chemical reactions and the products of
those reactions, including gas. In this investigation, you will be observing the gas in
!
greater detail. You will start by making a 100 mL stock solution of citric acid. This is
simply a supply from which you will draw a small amount for each trial. You will repeat
this experiment THREE (3) times and calculate the average result.
Materials
1
Jar of sodium bicarbonate
2
1
Jar of citric acid
2
1
Plastic cup
1
2
1
2

Spoons, 2-mL
Stirring stick
1

Glass bottles
Protective eyewear

Rubber stoppers, #1, with
hole
Syringes, 35-mL
Waste container
Tray or basin
Water
Graduated cylinder
Procedure
a.
b.
Gather the necessary materials for your group.
Get a bottle-and-syringe system for each pair.
c. Put on protective eyewear.
d.
e.
Read all of the following directions before starting.
Make a stock citric acid solution. Dissolve one
level, 2-mL spoon of citric acid in 100 mL of
water. This is your stock citric acid solution.
f.
Put on level, 2-mL spoon of sodium bicarbonate
g.
Take up exactly 5 mL of citric acid solution in the
h.
into the bottle.
syringe.
Twist the stopper onto the bottle.
Insert the tip of the syringe into the hole
of the bottle.
In one smooth, quick motion, push the solution
into the bottle.
Don’t remove the syringe.
Observe and record.
i. Dump the used experiment and conduct two
more trials. It is not necessary to wash out the
bottle between trials.
Results:
Questions for your group to discuss:
1. On average, how much gas formed when the citric acid and sodium bicarbonate reacted?
2. How much sodium bicarbonate was in the reaction bottle?
3. How much citric acid was in the reaction bottle?
4. How much citric acid did you add to the stock solution bottle?
5. How much stock solution did you add to the reaction bottle?
6. How much citric acid was in the 5 mL sample you pulled out of the stock solution bottle?
Name: _______________________
Period: _________
Date: ________
How Much Gas? Part B
Analysis/Summary of Lab
1. What caused the syringe plunger to go up during the reaction between citric acid and
sodium bicarbonate?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
2. Why is the syringe more useful than a balloon to conduct this experiment?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
3. What do you think might happen if you doubled the amount of citric acid?
Why?
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___________
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___________
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___________
_____________________________________________________________________________
___________
4. What do you think might happen if you double the amount of sodium bicarbonate?
Why?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
Discussion and Notes:
Name: _______________________
Period: _________
Date: ________
What’s in the Bubbles?
1. Make a list of the gases you know about or have heard about.
__________________________________
__________________________________
__________________________________
__________________________________
__________________________________
__________________________________
__________________________________
__________________________________
__________________________________
__________________________________
2. How would you define gas?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
3. Everything is made of elements (see your earlier work). What elements could be in the gas that
forms when sodium bicarbonate (NaHCO3) and citric acid (C6H8O7) react?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
4. What gas do you think is in the bubbles that form when NaHCO3 and C6H8O7 react?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
Discussion and Notes:
Name: _______________________
Period: _________
Date: ________
Discuss Air as Particles
This section of questions refers to the experiment involving a
piece of bubble wrap and syringe.
1. What is the air in the syringe (recent observations) and the air in the bubbles (well tray) made of?
_____________________________________________________________________________
___________
2. What happens to the gas particles in the syringe when you push on the plunger?
_____________________________________________________________________________
___________
3. What happens to the air particles in the bubble when you pull up on the plunger?
_____________________________________________________________________________
___________
4. Are there more air particles in the bubble when it is compressed or when it is expanded?
_____________________________________________________________________________
___________
5. When you push on the plunger, are the air particles closer together in the syringe or in the bubble?
_____________________________________________________________________________
___________
6. What is between the air particles?
_____________________________________________________________________________
___________
7. What happens to air particles when a volume of air is compressed?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
When a volume of air expands?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
Name: _______________________
Period: _________
Air in the Syringe A
Date: ________
Name: _______________________
Period: _________
Date: ________
Air as Particles B
1. How are the particles in syringe B drawn differently? Why did you draw them this way?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
2. How are the particles in syringe C drawn differently? Why did you draw them this way?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
3. How are the particles in syringe D drawn differently? Why did you draw them this way?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
4. How are the particles in syringe E drawn differently? Why did you draw them this way?
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
_____________________________________________________________________________
___________
5. Which illustration demonstrates air that is being compressed?
_____________________________________________________________________________
__________
Air that is being expanded?
_____________________________________________________________________________
___________
Discussion and Notes:
(Compression, expansion, and pressure will be discussed. You might choose to include drawings
and explanations)