,Chapter 1 - Chemistry and Measurement
1. What is a scientific theory?
A) It is a collection of experimental data.
B) It is an assertion of scientific fact.
C) It is a guess or conjecture about natural phenomena.
D) It is a fundamental relationship of nature.
E) It is an explanation of natural phenomena that has undergone significant testing.
ANS: E PTS: 1 DIF: easy REF: 1.2
OBJ: Understand how the scientific method is an approach to performing science.
TOP: general concepts | scientific method MSC: general chemistry
2. An untested explanation of a series of experimental observations is called .
A) a hypothesis
B) a theory
C) a law
D) an experiment
E) the scientific method
ANS: A PTS: 1 DIF: easy REF: 1.2
OBJ: Understand how the scientific method is an approach to performing science.
TOP: general concepts | scientific method
3. Which of the following statements concerning experiment and explanation is/are true?
1. A law is always given in the form of a mathematical expression.
2. Once a hypothesis passes one or two tests it is considered a theory.
3. Observation is a key component of the scientific method.
A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1, 2, and 3
ANS: C PTS: 1 DIF: easy REF: 1.2
OBJ: Understand how the scientific method is an approach to performing science.
TOP: general concepts | scientific method
4. A saline solution similar to that used for intravenous drips is made by dissolving 0.45 g
sodium chloride in 50.00 g water. Which of the following statements concerning the saline
solution and the law of conservation of mass is/are correct?
1. The mass of the saline solution is greater than the mass of water.
2. The mass of the saline solution is equal to the combined mass of sodium
chloride and water.
3. The mass of the saline solution is greater than the mass of the sodium
chloride.
, A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1, 2, and 3
ANS: D PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass.
TOP: general concepts | matter
5. A 19.0-g sample of lithium is completely burned in air to form lithium oxide. The mass of
lithium oxide must be
A) less than 19.0 g.
B) greater than 19.0 g.
C) equal to 19.0 g.
D) all of the above.
E) none of the above.
ANS: B PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass. (Example 1.1)
TOP: general concepts | matter
6. A sample of silicon is burned in oxygen to form silicon dioxide. What mass of oxygen is
consumed if 57.76 g silicon dioxide is formed from 27.00 g silicon?
A) 30.76 g
B) 84.76 g
C) 1559.59 g
D) 0.47 g
E) none of the above.
ANS: A PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass.
TOP: general concepts | matter
7. In a certain chemical reaction, 7.29 g of compound A is added to 5.70 g of compound B.
Once the reaction is complete, 3.60 g of compound A and 1.17 g of compound B remain.
What mass of products was produced?
A) 17.76 g
B) 4.53 g
C) 8.22 g
D) 3.69 g
E) 4.77 g
ANS: C PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass. (Example 1.1)
TOP: general concepts | matter KEY: Law of Conservation of Mass
MSC: general chemistry
8. A 5.77 g sample of calcium carbonate completely decomposes into calcium oxide (lime) and
carbon dioxide gas when heated. If 3.23 g calcium oxide is produced, what mass of carbon
dioxide must have been formed?
, A) 2.54 g
B) 9.00 g
C) 18.65 g
D) 0.56 g
E) 1.92 g
ANS: A PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass.
TOP: general concepts | matter
9. A sample of rubidium carbonate, weighing 7.00 g, requires 2.20 g of hydrogen chloride gas
to completely decompose to water, rubidium chloride, and carbon dioxide gas. The total
mass of water and rubidium chloride formed is 7.90 g and no hydrogen chloride or rubidium
carbonate remains. According to the law of conservation of mass, what mass of carbon
dioxide must have been formed?
A) 1.30 g
B) 0.90 g
C) 8.65 g
D) 17.10 g
E) 3.07 g
ANS: A PTS: 1 DIF: moderate REF: 1.3
OBJ: Apply the law of the conservation of mass.
TOP: general concepts | matter
10. Sodium oxide reacts with water to produce sodium hydroxide. Suppose 18.6 g of sodium
oxide is combined with 33.7 g of water. When the reaction is complete, all the sodium
oxide has been consumed. According to the law of conservation of mass, which is a true
statement?
A) The mass of sodium hydroxide produced must equal 52.3 g.
B) The mass of unreacted water must equal 15.1 g.
C) The mass of sodium hydroxide produced must equal 18.6 g.
D) The mass of water consumed must equal 18.6 g.
E) The mass of sodium hydroxide produced plus the mass of unreacted water must
equal 52.3 g.
ANS: E PTS: 1 DIF: difficult REF: 1.3
OBJ: Apply the law of the conservation of mass. (Example 1.1)
TOP: general concepts | matter KEY: Law of Conservation of Mass
MSC: general chemistry
11. After a certain chemical reaction has completed, it is found that 33.7 g of product was
produced. According to the law of conservation of mass, which statement must be true?
A) The total mass consumed of all reactants was 33.7 g.
B) The mass consumed of each reactant was 33.7 g.
C) The mass of reactants consumed depends on the number of reactants present.
D) Before the reaction started, there was 33.7 g total of all reactants.
E) Before the reaction started, there was 33.7 g of each reactant.
ANS: A PTS: 1 DIF: difficult REF: 1.3
OBJ: Apply the law of the conservation of mass. (Example 1.1)
1. What is a scientific theory?
A) It is a collection of experimental data.
B) It is an assertion of scientific fact.
C) It is a guess or conjecture about natural phenomena.
D) It is a fundamental relationship of nature.
E) It is an explanation of natural phenomena that has undergone significant testing.
ANS: E PTS: 1 DIF: easy REF: 1.2
OBJ: Understand how the scientific method is an approach to performing science.
TOP: general concepts | scientific method MSC: general chemistry
2. An untested explanation of a series of experimental observations is called .
A) a hypothesis
B) a theory
C) a law
D) an experiment
E) the scientific method
ANS: A PTS: 1 DIF: easy REF: 1.2
OBJ: Understand how the scientific method is an approach to performing science.
TOP: general concepts | scientific method
3. Which of the following statements concerning experiment and explanation is/are true?
1. A law is always given in the form of a mathematical expression.
2. Once a hypothesis passes one or two tests it is considered a theory.
3. Observation is a key component of the scientific method.
A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1, 2, and 3
ANS: C PTS: 1 DIF: easy REF: 1.2
OBJ: Understand how the scientific method is an approach to performing science.
TOP: general concepts | scientific method
4. A saline solution similar to that used for intravenous drips is made by dissolving 0.45 g
sodium chloride in 50.00 g water. Which of the following statements concerning the saline
solution and the law of conservation of mass is/are correct?
1. The mass of the saline solution is greater than the mass of water.
2. The mass of the saline solution is equal to the combined mass of sodium
chloride and water.
3. The mass of the saline solution is greater than the mass of the sodium
chloride.
, A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1, 2, and 3
ANS: D PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass.
TOP: general concepts | matter
5. A 19.0-g sample of lithium is completely burned in air to form lithium oxide. The mass of
lithium oxide must be
A) less than 19.0 g.
B) greater than 19.0 g.
C) equal to 19.0 g.
D) all of the above.
E) none of the above.
ANS: B PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass. (Example 1.1)
TOP: general concepts | matter
6. A sample of silicon is burned in oxygen to form silicon dioxide. What mass of oxygen is
consumed if 57.76 g silicon dioxide is formed from 27.00 g silicon?
A) 30.76 g
B) 84.76 g
C) 1559.59 g
D) 0.47 g
E) none of the above.
ANS: A PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass.
TOP: general concepts | matter
7. In a certain chemical reaction, 7.29 g of compound A is added to 5.70 g of compound B.
Once the reaction is complete, 3.60 g of compound A and 1.17 g of compound B remain.
What mass of products was produced?
A) 17.76 g
B) 4.53 g
C) 8.22 g
D) 3.69 g
E) 4.77 g
ANS: C PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass. (Example 1.1)
TOP: general concepts | matter KEY: Law of Conservation of Mass
MSC: general chemistry
8. A 5.77 g sample of calcium carbonate completely decomposes into calcium oxide (lime) and
carbon dioxide gas when heated. If 3.23 g calcium oxide is produced, what mass of carbon
dioxide must have been formed?
, A) 2.54 g
B) 9.00 g
C) 18.65 g
D) 0.56 g
E) 1.92 g
ANS: A PTS: 1 DIF: easy REF: 1.3
OBJ: Apply the law of the conservation of mass.
TOP: general concepts | matter
9. A sample of rubidium carbonate, weighing 7.00 g, requires 2.20 g of hydrogen chloride gas
to completely decompose to water, rubidium chloride, and carbon dioxide gas. The total
mass of water and rubidium chloride formed is 7.90 g and no hydrogen chloride or rubidium
carbonate remains. According to the law of conservation of mass, what mass of carbon
dioxide must have been formed?
A) 1.30 g
B) 0.90 g
C) 8.65 g
D) 17.10 g
E) 3.07 g
ANS: A PTS: 1 DIF: moderate REF: 1.3
OBJ: Apply the law of the conservation of mass.
TOP: general concepts | matter
10. Sodium oxide reacts with water to produce sodium hydroxide. Suppose 18.6 g of sodium
oxide is combined with 33.7 g of water. When the reaction is complete, all the sodium
oxide has been consumed. According to the law of conservation of mass, which is a true
statement?
A) The mass of sodium hydroxide produced must equal 52.3 g.
B) The mass of unreacted water must equal 15.1 g.
C) The mass of sodium hydroxide produced must equal 18.6 g.
D) The mass of water consumed must equal 18.6 g.
E) The mass of sodium hydroxide produced plus the mass of unreacted water must
equal 52.3 g.
ANS: E PTS: 1 DIF: difficult REF: 1.3
OBJ: Apply the law of the conservation of mass. (Example 1.1)
TOP: general concepts | matter KEY: Law of Conservation of Mass
MSC: general chemistry
11. After a certain chemical reaction has completed, it is found that 33.7 g of product was
produced. According to the law of conservation of mass, which statement must be true?
A) The total mass consumed of all reactants was 33.7 g.
B) The mass consumed of each reactant was 33.7 g.
C) The mass of reactants consumed depends on the number of reactants present.
D) Before the reaction started, there was 33.7 g total of all reactants.
E) Before the reaction started, there was 33.7 g of each reactant.
ANS: A PTS: 1 DIF: difficult REF: 1.3
OBJ: Apply the law of the conservation of mass. (Example 1.1)
