Chapter 17:
Classification of Matter
Practice Test
1.
The mass of the products produced by a chemical reaction is measured. The reaction is repeated five times, with the same mass of reactants used each time. The measured product masses are 50.17 g, 50.12 g, 50.17 g, 50.10 g, and 50. 14 g. What is the average of these measurements?
a.
50.10 g
b.
50.14 g
c.
50.17 g
d.
50.13 g
Hint
2.
The size of particles in a solution are on the order of 1 nm, with 1 nm being equal to 0.000000001 m. Write 0.000000001 m in scientific notation.
a.
1 × 10
8
m
b.
1 × 10
-9
m
c.
1 × 10
-8
m
d.
1 × 10
9
m
Hint
3.
Water breaks down into hydrogen gas and oxygen gas according to the reaction 2H
2
O → 2H
2
+ O
2
. In this reaction the mass of oxygen produced is eight times greater than the mass of hydrogen produced. If 36 g of water form hydrogen and oxygen gas, what is the mass of hydrogen gas produced?
a.
4 g
b.
8 g
c.
32 g
d.
18 g
Hint
4.
The human body is about 65% oxygen. If a person has a mass of 75.0 kg, what is the mass of oxygen in their body?
a.
26.2 kg
b.
65 kg
c.
10 kg
d.
48.8 kg
Hint
5.
A chemical reaction produces two products, one with a mass of 34 g and the other with a mass of 39 g. What was the total mass of the reactants?
a.
5 g
b.
34 g
c.
39 g
d.
73 g
Hint
6.
Saltwater is distilled by boiling the saltwater and condensing the vapor. After distillation, 1,164 g of water have been collected and 12 g of salt are left behind in the original container. What was the original mass of the saltwater?
a.
1,164 g
b.
128 g
c.
1,176 g
d.
1,152 g
Hint
7.
Write the number 78,300,000 in scientific notation.
a.
7.83 × 10
-7
b.
7.83 × 10
7
c.
7.83 × 10
-6
d.
783 × 10
5
Hint
8.
Calcium carbonate, CaCO
3
, decomposes according to the reaction: CaCO
3
→ CaO + CO
2
. When 250 g of CaCO
3
decompose completely, the mass of CaO is 56% of the mass of the products of this reaction. What is the mass of CO
2
produced?
a.
110 g
b.
250 g
c.
140 g
d.
390 g
Hint
9.
Carbon reacts with oxygen to form carbon dioxide according to the following equation: C + O
2
→ CO
2
. When 120 g of carbon reacts with oxygen, 440 g of carbon dioxide are formed. How much oxygen reacted with the carbon?
a.
320 g
b.
440 g
c.
560 g
d.
120 g
Hint
10.
Two solutions, one with a mass of 450 g and the other with a mass of 350 g, are mixed. A chemical reaction occurs and 125 g of solid crystals are produced that settle on the bottom of the container. What is the mass of the remaining solution?
a.
100 g
b.
225 g
c.
800 g
d.
675 g
Hint
