ALL WORK IS DONE IN YOUR
NOTEBOOK DO NOT WRITE ON THE
PACKET!
Matter and Change
Part 1
Understanding Elements, Compounds, and Mixtures
Over the course of this Chemistry unit we will try to answer the question “How do we know if
we have made something new of simply have a mixture?” Before we can know the answer to
that question we must investigate matter at the microscopic level. Examine the set of models
provided for you and answer the following questions in your notebook.
1.
Which would you call atoms? Why?
Which would you call molecules? Why?
Which do you think are elements? Why?
Which do you think are compounds? Why?
2.
Discuss in your group whether there are any relationships between the categories above.
For instance, is an atom always one element? Are elements always present as one atom?
Identify at least two relationships.
3.
Use the models to show a mixture of three of the different substances represented and
sketch it in your notebook.
Demonstrate what happens when two substances react chemically and sketch it in your
notebook. How is this fundamentally different from “mixing” any of the two? Be
prepared to share your reasoning and results with the larger group.
Label which has sketch represents a physical change and which would represent a
chemical change.
4.
5.
Part 2
The Macroscopic Level
1.
In this activity, you will work with your group to answer the same kinds of questions
and do the same kinds of things as in Part 1, but with actual samples of matter. Examine
the samples of matter that have been provided. Feel free to touch, smell and even taste
them (although most are not edible). Classify them as elements, compounds, or
mixtures.
ElementsCompoundsMixtures-
2.
3.
4.
5.
Is it possible for one of the samples to fall into more than one of the classification
categories above?
Is it possible that a sample may not fit into any of these categories?
Can you think of any instruments or tests that might help you decide whether a certain
material is an element, compound or mixture?
Could any of the samples be a solution? Are there any samples that are definitely not a
solution?
Possibly SolutionsNot Solutions-
6.
7.
8.
9.
Decide in your group which two samples could be mixed together to produce a chemical
reaction. DON’T MIX THEM YET! HOLD YOUR FREAKIN HORSES! Why did you
choose these two?
Now, mix your two chosen samples together. Can you say for certain that a chemical
reaction has or has not taken place? How do you know?
Think back to what you did in part 1. Which was more difficult Part 1 or Part 2 and
why?
Is if difficult to see the connections between the particle models in Part 1 and the real
sample of matter in Part2? What make it difficult?
Part 3
Solids in Water
1.
2.
3.
Put water into your clear containers until each is about ¾ full. Add two spoonfuls of a
different solid to each container and stir. Wait a few minutes, noticing any changes that
occur in the containers as time passes. Designate the mixtures as homogenous or
homogenous. Create a chart to record your data.
Use the hand lens and the flashlight to observe the contents of the containers more
closely. When you shine the flashlight through the water in a container, place a sheet of
white paper behind the container to aid your observation. Make observations about how
the beam is visible in and out of the mixture.
For each mixture draw a picture showing in what way you think the particles (atoms or
molecules) of the two substances are arranged or distributed that might account for your
observations. Use two different colors to represent the particles of the two substances.
Sand/
Water
4.
Dirt/
Water
Flour/
Water
Creamer
/Water
Sugar/
Water
How could you remove the flour from the water? How could you get back the sugar
from the water?
5.
Find the definitions for colloid and suspension in your book.
Separating Mixtures
Part 1
Butter or Margarine?
1.
2.
3.
4.
5.
6.
Obtain pats of equal volume of butter, margarine and light margarine. Place them
immediately in three separate test tubes using wooden craft sticks. Place the test
tubes in a water bath and heat until the butter or margarine in each tube melts.
Measure and record the height of each ingredient in each tube. Describe the
differences among the contents of the three tubes. Do any of the tubes only contain
one substance?
Compare the relative percentage of each component in the tubes to the ingredients
found on the package. Which product would you buy and why?
What was the difference in properties of the substances in the butter or margarine
that enabled you to separate them?
Think of an everyday example of mixtures that are separated based on this
difference.
What kinds of mixtures in general can be separated using this same kind of
procedure?
Part 2
Mystery Ink
You have confiscated a letter that was passed to your girlfriend (or boyfriend). The letter is
written in invisible ink but is signed with a black marker: XXO. Who is trying to move in on
your significant other? You suspect 5 different people; luckily for you they all use different
brands of pens. You will use chromatography to distinguish which brand the black ink
belongs to.
a. Obtain a strip of chromatography paper (only handle the edges). Place it on a clean
piece of paper and, with a pencil, make a line 1 cm from the bottom of the paper.
Then, make a series of small dots about 1.5 cm apart along the line, over which you
will place a small spot of ink from each brand of pen. Mark each dot in pencil with
the initials of he manufacturer of the pen for identification purposes. The dot should
be small, about 2 mm in diameter.
b. Pour about 25 mL of water or rubbing alcohol into a 600 mL beaker.
c. Attach the paper to a straw with a piece of tape so that the edge of the paper is just
touching the water or alcohol.
d. Allow the paper to sit until the ink is no longer traveling. Take it out and let it dry.
e. Do the same with the piece torn from the confiscated note with the XXO to determine
who wrote the note.
1.
2.
Which pen was used to make the mystery writing? Explain how you reached
your conclusion.
What was the difference in properties in the pigments of the black ink that
allowed them to be separated by chromatography?
3.
4.
What other mixtures could be separated using chromatography?
Design and make a reference chart for determining what separation
technique to use with different kinds of mixtures.
Chemical Reactions
When does Mixing Substances Result in a Chemical Reaction?
1.
2.
Part 1
Looking for Something New: What Are the Clues?
Working in your group you will examine some selected chemical reactions. Questions
you will need to answer for each reaction are
a. What two substances are reacting?
b. What changes do you observe?
c. How do you know this is a chemical reaction? (If there is temperature changes
decide if the reaction is endothermic or exothermic.)
d. What instruments or tests might make it easier to know what is happening?
Create a chart in your notebook to record this data.
After performing these chemical reactions. Look over all the data your group collected.
What kind of clues are indicators of a chemical reaction? Make a list of clues to look for
that will help identify chemical reactions.
Conclusion
Create a flow chart that relates all the terms from the chapter to one another- they are listed on
the board. Be prepared to defend your chart.