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Chemistry for Changing Times, 14e (Hill/McCreary)
Chapter 2 Atoms
2.1 Multiple Choice Questions
1) The Greek word atomos means
A) atom.
B) uncuttable.
C) invisible.
D) continuous.
2) Leucippus and Democritus proposed the “first” atomic view of matter. They arrived at this view based
on
A) many experiments.
B) careful measurements.
C) philosophical and intuitive speculation.
D) All of the above contributed to their atomic view.
3) The ancient Greeks believed that matter was composed of four basic elements. Which one of the
following was NOT one of the four?
A) mercury
B) air
C) water
D) earth
4) How many years ago was an atomic view of matter was first proposed?
A) 50
B) 100
C) 200
D) 2500
5) Which philosopher believed that matter was continuous and was not made up of atoms?
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A) Aristotle
B) Dalton
C) Democritus
D) Lavoisier
6) Leucippus and Democritus believed that all of the following statements about matter were true
EXCEPT
A) Matter was made up of atoms.
B) Each type of matter had a distinctive size and shape.
C) Matter was continuous.
D) Substances are mixtures of different kinds of atoms.
7) Which of the following statements about atoms is NOT true?
A) Atoms are too small to be seen even with a microscope.
B) Atoms make up every material.
C) Atoms are the smallest particles that are characteristic of a given element.
D) No atoms have been synthesized by scientists.
8) Approximately how many elements occur naturally on Earth?
A) 20
B) 60
C) 90
D) 115
9) The “father of modern chemistry” is
A) Boyle.
B) Lavoisier.
C) Mendeleev.
D) Proust.
10) 32 g of sulfur will react with 48 g of oxygen to produce 80 g of sulfur trioxide. If 16 g of sulfur and 100
g of oxygen are placed into a sealed container and allowed to react, what is the mass of the material in the
container after the reaction is completed?
A) 40 g
B) 16 g
C) 100 g
D) 116 g
11) 32 g of sulfur will react with 48 g of oxygen to produce 80 g of sulfur trioxide. If 16 g of sulfur and 100
g of oxygen are placed into a sealed container and allowed to react, what is the mass of sulfur trioxide in
the container after the reaction is completed?
A) 40 g
B) 16 g
C) 100 g
D) 116 g
12) By definition, which of the following can be broken down into simpler substances?
A) compound
B) atom|ion
C) solid
D) liquid
13) Lavoisier performed many of the same experiments as his predecessors. The one thing that most
distinguished Lavoisier‘s work was
A) the results.
B) the mass measurements.
C) the chemicals.
D) the glassware.
14) Lavoisier measured the mass of substances before and after chemical reactions and summarized his
observations in a(n)
A) hypothesis.
B) observation.
C) theory.
D) law.
15) Which one of the following statements is NOT a correct statement of the Law of Conservation of
Mass?
A) The mass of a system is dependent upon chemical reactions that may occur.
B) The mass of a system is conserved in a chemical reaction.
C) Matter cannot be created or destroyed.
D) Atoms are conserved in chemical reactions.
16) A mixture containing 50 grams of carbon and 75 grams of oxygen is sealed in a flask. The total mass
of the system is 225 grams. The flask is heated to cause the carbon and oxygen to react. The sealed flask
is massed. What is the mass of the sealed flask?
A) 125 grams
B) 150 grams
C) 175 grams
D) 225 grams
17) A student measures 10.5 g of mercury(II) oxide into an open test tube and heats the tube. The heat
causes the mercury(II) oxide to decompose into mercury and oxygen. After reaction, the student finds
the mass of the contents of the tube to be 9.7 g. Which one of the following describes these observations?
A) The decomposition of mercury(II) oxide does not obey the Law of Conservation of Mass.
B) 0.8 grams of oxygen gas are lost from the tube.
C) There are errors associated with the student’s measurements.
D) Heating destroys some mass.
18) The amount of carbon on the earth, including the atmosphere,
A) is essentially constant.
B) is decreasing due to consumption of carbon based fuels, such as coal and petroleum.
C) is increasing due to plant and animal growth on the planet.
D) fluctuates dramatically with the seasons.
19) The amount of aluminum on the earth today relative to the amount 100 years ago when Al was first
commercially extracted from bauxite, an aluminum containing ore,
A) is essentially the same.
B) is decreasing rapidly due to production of aluminum beverage containers.
C) is decreasing, but more slowly recently due to interest in recycling.
D) is actually increasing due to recycling efforts and more energy efficient production methods.
20) Hydrogen peroxide decomposes into water and oxygen when exposed to heat or light. A tightly
capped bottle of hydrogen peroxide is placed on a mass scale (a balance) and exposed to light for three
weeks. The mass reading on the scale does not change. This is an example of
A) the Law of Conservation of Mass.
B) the Law of Definite Proportions.
C) the Law of Constant Composition.
D) the Law of Multiple Proportions.
21) Methane can be decomposed into two simpler substances, hydrogen and carbon. Therefore, methane
A) is a solid.
B) cannot be an element.
C) must be a mixture.
D) must have the formula CH2.
22) The ability to recycle aluminum (or glass, or plastic) is ultimately an illustration of
A) the Law of the Conservation of Mass.
B) the Law of Definite Proportions.
C) the ingenuity of chemists.
D) the Law of Multiple Proportions.
23) When electricity is passed through molten potassium bromide, two simpler substances, potassium
and bromine, are produced. Therefore, potassium bromide
A) cannot be an element.
B) must be a mixture.
C) has less mass than the resulting potassium and bromine do.
D) must have the formula PB.
24) The Law of Definite Proportions was first stated by
A) Lavoisier.
B) Galileo.
C) Dalton.
D) Proust.
25) When added to a sealed flask and heated, 6.0 g of carbon and 16.0 g of oxygen react to form 22.0 g of
carbon dioxide. How much carbon dioxide is formed when 24.0 g of carbon is reacted with 100.0 g of
oxygen?
A) 40.0 g
B) 44.0 g
C) 88.0 g
D) 112.0 g
26) The observation that 10 g of hydrogen gas always combines with 80 g of oxygen gas to form 90 g of
water, even when there is more than 80 g of oxygen present in the reaction container, illustrates the Law
of
A) Definite Proportions.
B) Multiple Proportions.
C) ideal gases.
D) excess reactants.
27) No matter how much extra oxygen is available, 12 grams of carbon always combines with 32 grams of
oxygen. This best illustrates the Law of
A) Conservation of Mass.
B) Definite Proportions.
C) Multiple Proportions.
D) Conservation of Energy.
28) Heptane is always composed of 84.0% carbon and 16.0% hydrogen. This illustrates the Law of
A) Conservation of Mass.
B) Definite Proportions.
C) Multiple Proportions.
D) all of the above
29) When 10.00 g of lead and 1.56 grams of sulfur react, 11.56 g of lead sulfide is produced. Suppose 30.00
g of lead and 1.56 g of sulfur are allowed to react. Analysis of the reaction mixture would show
A) 31.56 g of lead sulfide.
B) 34.68 g of lead sulfide.
C) 11.56 g of lead sulfide and 20.00 g of lead.
D) no reaction.
30) 2 g of sulfur will react with 3 g of oxygen to produce 5 g of sulfur trioxide. If 54 g of sulfur and 100 g
of oxygen are placed into a sealed container and allowed to react, how much sulfur dioxide will be
produced?
A) 54 g
B) 81 g
C) 135 g
D) 154 g
31) Sample A contains 92.3%carbon and 7.7% hydrogen. If sample B is the same substance, it will contain
A) 80% carbon and 20% hydrogen.
B) 92.3% carbon and 7.7% hydrogen.
C) 83.3% carbon and 16.7% hydrogen.
D) 85% carbon and 15% hydrogen.
32) CO2 always contains 3 g of C for every 8 g of O. This is an example of
A) Dalton’s Atomic Theory.
B) Lavoisier’s Law of Conservation of Mass.
C) Dalton’s Law of Multiple Proportions.
D) Proust’s Law of Definite Proportions.
33) When 28 g of nitrogen and 6 g of hydrogen react, 34 g of ammonia are produced. If 80 g of nitrogen
react with 4 g of hydrogen, how much ammonia will be produced?
A) 22.6 g
B) 43 g
C) 50 g
D) 4 g
34) Which of the following can be broken down into simpler substances?
A) CO
B) Se
C) Mg
D) F
35) Which of the following parts (postulates) of Dalton’s atomic theory has been modified in light of later
discoveries?
A) All matter is made up of very small particles called atoms.
B) Atoms are indivisible.
C) Chemical reactions involve rearrangement of atoms.
D) Compounds are formed from atoms.
36) Which of the following laws is NOT explained by Dalton’s atomic theory?
A) the Law of Conservation of Mass
B) the Law of Definite Proportions
C) the Law of Multiple Proportions
D) the periodic law
37) ________ was the first person to propose a consistent “modern” atomic theory.
A) Dalton
B) Democritus
C) Proust
D) Lavoisier
38) Which discovery was NOT in conflict with Dalton’s atomic theory?
A) the discovery of electrical charge
B) the discovery of the electron
C) the discovery of the element gallium
D) the discovery of the proton
39) Which of the following was NOT explained by Dalton’s atomic theory?
A) the Law of Conservation of Mass
B) the Law of Multiple Proportions
C) the difference between isotopes of an element
D) the difference between elements and compounds
40) After many observations, Proust stated that elements combine in definite proportions to form
compounds. Dalton explained these observations by proposing that matter must consist of atoms.
Dalton’s explanation is called a(n)
A) law.
B) theory.
C) hypothesis.
D) observation.
41) Nitrogen forms a number of different compounds with oxygen, depending upon the experimental
conditions. This type of observation concerning the behavior of matter is summarized by
A) the Law of Conservation of Mass.
B) the Law of Definite Proportions.
C) the Law of Constant Composition.
D) the Law of Multiple Proportions.
42) Which one of the following is NOT part of Dalton’s atomic theory?
A) Matter is composed of atoms.
B) Atoms of the same element have the same properties.
C) Atoms of different elements have different properties.
D) Atoms change into other atoms in chemical reactions.
43) Although all parts (postulates) of Dalton’s atomic theory are important, which one of the postulates is
crucial to explain the observations summarized by the Law of Definite Proportions?
A) Matter is composed of atoms.
B) Atoms of the same element have the same properties.
C) Atoms combine with other atoms in fixed, whole number ratios to form compounds.
D) Atoms are very small.
44) Which one of the following does NOT occur in a chemical reaction?
A) Matter is rearranged.
B) Matter is conserved.
C) Atoms react with other atoms.
D) Atoms are changed into other atoms.
45) Dalton explained the Law of Conservation of Mass by stating that atoms are neither created nor
destroyed in a chemical reaction. Dalton’s explanation is an example of a scientific
A) theory.
B) law.
C) hypothesis.
D) experiment.
46) Which set of compounds illustrates the Law of Multiple Proportions?
A) NH3, PH3, AsH3
B) CH3, CF3, CCl3
C) NH3, N2H4
D) all of these
47) Which set of compounds illustrates the Law of Multiple Proportions?
A) CH4, C2H6, C3H8
B) NO, NH3, NH4Cl
C) H2O, H2
D) all of these