Question 1

The number of moles of H2O formed when 1 mole of O2 reacts with C5H12 in the reaction C5H12 + 8O2  →\rarr→ 5CO2 + 6H2O is

Accepted Answer

A)  3/4.
B)  4/3.
C)  6.
D)  8. E) A) and C)
F) A) and B)

Question 2

A storage battery stores

Accepted Answer

A)  electrons.
B)  electric current.
C)  energy.
D)  voltage.E) None of the above
F) A) and D)

Question 3

An enzyme is a

Accepted Answer

A)  gasoline additive that reduces pollution.
B)  constituent of natural gas.
C)  solvent used in electrolysis.
D)  biological catalyst.E) B) and D)
F) All of the above

Question 4

According to Aristotle, every flammable material consisted of

Accepted Answer

A)  earth and fire.
B)  phlogiston.
C)  oxygen and earth.
D)  air and heat.E) B) and C)
F) A) and C)

Question 5

The number of moles of O2 needed to react with 10 moles of C2H2 in the reaction 2C2H2 + 5O2  →\rarr→  4CO2 + 2H2O is

Accepted Answer

A)  5.
B)  10.
C)  25.
D)  50. E) A) and C)
F) B) and C)

Question 6

The decomposition of an unstable compound usually

Accepted Answer

A)  occurs only at low temperatures.
B)  requires a catalyst to occur.
C)  is endothermic.
D)  is exothermic.E) B) and C)
F) A) and D)

Question 7

The number of moles of atomic oxygen in 2 moles of Ca3(PO4) 2 is

Accepted Answer

A)  2.
B)  4.
C)  8.
D)  16.E) All of the above
F) C) and D)

Question 8

An example of slow oxidation is

Accepted Answer

A)  a lighted candle.
B)  the rusting of iron.
C)  the lighting of a match.
D)  a log burning in a fireplace.E) A) and C)
F) All of the above B

Question 9

Which of the following statements about ozone is incorrect?

Accepted Answer

A)  The formula of ozone is O3.
B)  Ozone molecules are more stable than those of ordinary oxygen.
C)  At low altitudes ozone contributes to smog.
D)  At high altitudes ozone absorbs solar ultraviolet radiation.E) A) and D)
F) A) and C)

Question 10

Silicon has an atomic mass of 28 u and Avogadro's number is 6 * 1023 formula units/mole.The mass of Avogadro's number of silicon atoms is

Accepted Answer

A)  1 g.
B)  28 g.
C)  6 * 1023 g.
D)  1.68 * 1025 g.E) B) and D)
F) B) and C)

Question 11

Oxidation-reduction reactions involve the transfer between the reacting substances of

Accepted Answer

A)  electrons.
B)  H+ ions.
C)  O2- ions.
D)  O2 molecules.E) All of the above
F) A) and B)

Question 12

The speed of a chemical reaction is not affected by

Accepted Answer

A)  the surface area of the reactants.
B)  catalysts.
C)  the concentration of reactants.
D)  the type of bond in reaction products.E) C) and D)
F) A) and B)

Question 13

When a substance loses electrons in a chemical reaction, the substance is said to be

Accepted Answer

A)  reduced.
B)  oxidized.
C)  dissociated.
D)  activated.E) A) and D)
F) A) and B)

Question 14

Sulfur has an atomic mass of 32 u and Avogadro's number is 6 * 1023 formula units/mole.The number of sulfur atoms in 1 mole of sulfur is

Accepted Answer

A)  32.
B)  1.9 * 1022.
C)  6 * 1023.
D)  1.9 * 1025.E) B) and D)
F) All of the above

Question 15

The proportion of oxygen in dry air is about

Accepted Answer

A)  1/5.
B)  1/3.
C)  1/2.
D)  4/5.E) All of the above
F) A) and D) A

Question 16

Which of the following compounds is not classed as an oxide?

Accepted Answer

A)  CO2.
B)  SiO2.
C)  BaSO4.
D)  H2O.E) A) and B)
F) C) and D)

Question 17

An oxide decomposed by heating will give

Accepted Answer

A)  oxygen and another element.
B)  CO2 and water.
C)  oxygen ions and metal ions.
D)  a metal and water.E) A) and B)
F) All of the above A

Question 18

The number of formula units in a mole of a substance

Accepted Answer

A)  depends on the formula mass of the substance.
B)  depends on whether the substance is an element or a compound.
C)  depends on whether the substance is a gas, a liquid, or a solid.
D)  is the same for all substances.E) B) and D)
F) A) and B)

Question 19

The atomic mass of N is 14 u and that of Ca is 40 u.The proportion of N by mass in the compound Ca3N2 is

Accepted Answer

A)  19 percent.
B)  35 percent.
C)  40 percent.
D)  81 percent.E) None of the above
F) All of the above

Question 20

Silicon has an atomic mass of 28 u and Avogadro's number is 6 * 1023 formula units/mole.The mass of 1 mole of silicon is

Accepted Answer

A)  1 g.
B)  28 g.
C)  6 * 1023 g.
D)  1.68 * 1025 g.E) None of the above
F) A) and B)

Exam 12: Chemical Reactions

The number of moles of H2O formed when 1 mole of O2 reacts with C5H12 in the reaction C5H12 + 8O2 →\rarr→ 5CO2 + 6H2O is

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A storage battery stores

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An enzyme is a

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According to Aristotle, every flammable material consisted of

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The number of moles of O2 needed to react with 10 moles of C2H2 in the reaction 2C2H2 + 5O2 →\rarr→ 4CO2 + 2H2O is

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The decomposition of an unstable compound usually

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The number of moles of atomic oxygen in 2 moles of Ca3(PO4) 2 is

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An example of slow oxidation is

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Which of the following statements about ozone is incorrect?

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Silicon has an atomic mass of 28 u and Avogadro's number is 6 * 1023 formula units/mole.The mass of Avogadro's number of silicon atoms is

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Oxidation-reduction reactions involve the transfer between the reacting substances of

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The speed of a chemical reaction is not affected by

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When a substance loses electrons in a chemical reaction, the substance is said to be

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Sulfur has an atomic mass of 32 u and Avogadro's number is 6 * 1023 formula units/mole.The number of sulfur atoms in 1 mole of sulfur is

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The proportion of oxygen in dry air is about

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Which of the following compounds is not classed as an oxide?

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An oxide decomposed by heating will give

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The number of formula units in a mole of a substance

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The atomic mass of N is 14 u and that of Ca is 40 u.The proportion of N by mass in the compound Ca3N2 is

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Silicon has an atomic mass of 28 u and Avogadro's number is 6 * 1023 formula units/mole.The mass of 1 mole of silicon is

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The number of moles of H₂O formed when 1 mole of O₂ reacts with C₅H₁₂ in the reaction C₅H₁₂ + 8O₂ $\rarr$ 5CO₂ + 6H₂O is

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The number of moles of O₂ needed to react with 10 moles of C₂H₂ in the reaction 2C₂H₂ + 5O₂ $\rarr$ 4CO₂ + 2H₂O is

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The number of moles of atomic oxygen in 2 moles of Ca₃(PO₄) ₂ is

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B

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Silicon has an atomic mass of 28 u and Avogadro's number is 6 * 10²³ formula units/mole.The mass of Avogadro's number of silicon atoms is

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Sulfur has an atomic mass of 32 u and Avogadro's number is 6 * 10²³ formula units/mole.The number of sulfur atoms in 1 mole of sulfur is

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A

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A

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The atomic mass of N is 14 u and that of Ca is 40 u.The proportion of N by mass in the compound Ca₃N₂ is

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Silicon has an atomic mass of 28 u and Avogadro's number is 6 * 10²³ formula units/mole.The mass of 1 mole of silicon is

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