# Holt Chemistry

## Educators

EF
+ 2 more educators

### Problem 1

What is chemistry?

David C.

### Problem 2

What are the common physical states of
matter, and how do they differ from one
another?

EF
Eric F.

### Problem 3

Explain the difference between a physical
change and a chemical change.

Shante A.

### Problem 4

What units are used to express mass and
weight?

EF
Eric F.

### Problem 6

What is a conversion factor?

EF
Eric F.

### Problem 7

Explain what derived units are. Give an
example of one.

Ahmed A.

### Problem 8

Define density, and explain why it is considered a physical property rather than a
chemical property of matter.

EF
Eric F.

### Problem 9

Write a brief paragraph that
shows that you understand the
following terms and the relationships between them: atom, molecule,
compound, and element.

David C.

### Problem 10

What do the terms homogeneous and
heterogeneous mean?

EF
Eric F.

### Problem 11

Your friend mentions that she eats only
natural foods because she wants her food
to be free of chemicals. What is wrong with
this reasoning?

David C.

### Problem 12

Determine whether each of the following
substances would be a gas, a liquid, or a
solid if found in your classroom.
a. neon
b. mercury
c. sodium bicarbonate (baking soda)
d. carbon dioxide
e. rubbing alcohol

EF
Eric F.

### Problem 13

Is toasting bread an example of a chemical
change? Why or why not?

David C.

### Problem 14

Classify each of the following as a physical
change or a chemical change, and describe
the evidence that suggests a change is taking
place.
a. cracking an egg
b. using bleach to remove a stain from a shirt
c. burning a candle
d. melting butter in the sun

EF
Eric F.

### Problem 15

Name the five most common SI base units
used in chemistry. What quantity is each unit
used to express?

Brian H.

### Problem 16

What derived unit is appropriate for
expressing each of the following?
a. rate of water flow
b. speed
c. volume of a room

EF
Eric F.

### Problem 17

Compare the physical and chemical properties of salt and sugar. What properties do
they share? Which properties could you use
to distinguish between salt and sugar?

JE
Jan E.

### Problem 18

What do you need to know to determine the
density of a sample of matter?

EF
Eric F.

### Problem 19

Substances A and B are colorless, odorless

liquids that are nonconductors and flammable. The density of substance A is
0.97 g/mL; the density of substance B is
0.89 g/mL. Are A and B the same substance?

Kate D.

### Problem 20

Is a compound a pure substance or a mixture? Explain your answer.

EF
Eric F.

### Problem 21

Determine if each material represented
below is an element, compound, or mixture,
and whether the model illustrates a solid,
liquid, or gas.

David C.

### Problem 22

Which quantity of each pair is larger?
a. 2400 cm or 2 m
b. 3 L or 3 mL

EF
Eric F.

### Problem 23

Using Appendix A, convert the following
measurements to the units specified.
$$\begin{array}{ll}{\text { a. } 357 \mathrm{mL}=? \mathrm{L}} & {\text { d. } 2.46 \mathrm{L}=? \mathrm{cm}^{3}} \\ {\text { b. } 25 \mathrm{kg}=? \mathrm{mg}} & {\text { e. } 250 \mu \mathrm{g}=? \mathrm{g}} \\ {\text { c. } 35000 \mathrm{cm}^{3}=? \mathrm{L}} & {\text { f. } 250 \mu \mathrm{g}=? \mathrm{kg}}\end{array}$$

David C.

### Problem 24

Use particle models to explain why liquids
and gases take the shape of their containers.

EF
Eric F.

### Problem 25

You are given a sample of colorless liquid in
a beaker. What type of information could you
gather to determine if the liquid is water?

David C.

### Problem 26

Calculate the density of a piece of metal if
its mass is 201.0 $\mathrm{g}$ and its volume is 18.9 $\mathrm{cm}^{3} .$

EF
Eric F.

### Problem 27

The density of $\mathrm{CCl}_{4}$ (carbon tetrachloride)
is 1.58 $\mathrm{g} / \mathrm{mL} .$ What is the mass of 95.7 $\mathrm{mL}$ of
$\mathrm{CCl}_{4} ?$

David C.

### Problem 28

What is the volume of 227 g of olive oil if
its density is 0.92 g/mL?

EF
Eric F.

### Problem 29

A white, crystalline material that looks like
table salt releases gas when heated under
certain conditions. There is no change in the
appearance of the solid, but the reactivity of
the material changes.
a. Did a chemical or physical change occur?
How do you know?
b. Was the original material an element or a

David C.

### Problem 30

A student leaves an uncapped watercolor
marker on an open notebook. Later, the student discovers the leaking marker has produced a rainbow of colors on the top page.

a. Is this an example of a physical change or
b. Should the ink be classified as an element, a compound, or a mixture? Explain

EF
Eric F.

### Problem 31

Your teacher will provide you with a sample
of a metallic element. Determine its density.
Check references that list the density of metals to identify the sample that you analyzed.

David C.

### Problem 32

Make a poster showing the types of product
warning labels that are found on products in

Check back soon!

### Problem 33

Use the following terms to create a concept
map: volume, density, matter, physical property, and mass.

David C.

### Problem 34

What does the straight line on the graph
volume and mass?

EF
Eric F.

### Problem 35

What does the slope of each line indicate?

David C.

### Problem 36

What is the density of metal $\mathrm{A}$ ? of metal $\mathrm{B} ?$

EF
Eric F.

### Problem 37

Based on the density values in Table $4,$ what
do you think is the identity of metal A? of

David C.

### Problem 38

Graphing Tabular Data
The graphing calculator can run a program
that graphs ordered pairs of data, such as
temperature versus time. In this problem,
you will answer questions based on a graph
of temperature versus time that the calculator will create.

Go to Appendix C. If you are using a TI-83
data sets and run the application as directed.
Press the APPS key on your calculator, and
then choose the application CHEMAPPS.
Press 1, then highlight ALL on the screen,
press 1, then highlight LOAD, and press 2 to
application, and then run the program
GRAPH. A set of data points representing
degrees Celsius versus time in minutes will
be graphed.

If you are using another calculator, your
teacher will provide you with keystrokes
and data sets to use.
a. Approximately what would the temperature be at the 16-minute interval?
b. Between which two intervals did the temperature increase the most: between 3
and 5 minutes, between 5 and 8 minutes,
or between 8 and 10 minutes?
c. If the graph extended to 20 minutes, what
would you expect the temperature to be?

Check back soon!