Question 1

The number of calcium atoms in 1 g of calcium is

Accepted Answer

A) 40. 
B) 1.5 * 1022. 
C) 3 * 1022. 
D) 6 * 1023. 
A) 40. 
B) 1.5 * 1022. 
C) 3 * 1022. 
D) 6 * 1023.

Question 2

The yield of the product C in the reversible reaction A + B   C + energy can be increased by

Accepted Answer

A) decreasing the temperature. 
B) increasing the temperature. 
C) increasing the surface area of the reactants. 
D) changing the catalyst. 
A) decreasing the temperature. 
B) increasing the temperature. 
C) increasing the surface area of the reactants. 
D) changing the catalyst.

Question 3

The chief reason why reaction rates increase with temperature is that a rise in temperature increases the number of

Accepted Answer

A) ions. 
B) polar molecules. 
C) fast-moving molecules. 
D) activated molecules. 
A) ions. 
B) polar molecules. 
C) fast-moving molecules. 
D) activated molecules.

Question 4

If a certain reaction is endothermic, the reverse reaction

Accepted Answer

A) cannot occur. 
B) may occur spontaneously. 
C) cannot occur spontaneously. 
D) absorbs energy. 
A) cannot occur. 
B) may occur spontaneously. 
C) cannot occur spontaneously. 
D) absorbs energy.

Question 5

Ammonia gas dissolves in water and can react according to the equation NH3 + H2O   NH4+ OH-.The amount of ammonium ion in solution will be increased by which one or more of the following?

Accepted Answer

A) Increase the pressure of NH3 above the solution. 
B) Pump off the gas above the solution. 
C) Raise the temperature of the solution. 
D) Add HCl to the solution. 
E) Both A and D 
A) Increase the pressure of NH3 above the solution. 
B) Pump off the gas above the solution. 
C) Raise the temperature of the solution. 
D) Add HCl to the solution. 
E) Both A and D

Question 6

Oxidation-reduction reactions are not involved in

Accepted Answer

A) electrolysis. 
B) acid-base neutralization. 
C) the operation of a storage battery. 
D) the operation of a fuel cell. 
A) electrolysis. 
B) acid-base neutralization. 
C) the operation of a storage battery. 
D) the operation of a fuel cell.

Question 7

The number of moles of Al needed to react with each mole of CuSO4 in the reaction 2Al + 3CuSO4 $\rarr$ 3 Cu + Al2(SO4)3 is

Accepted Answer

A) 1/3. 
B) 1/2. 
C) 2/3. 
D) 3/2. 
A) 1/3. 
B) 1/2. 
C) 2/3. 
D) 3/2.

Question 8

For a reaction that takes place near room temperature, an increase of 10$\circ$C

Accepted Answer

A) has almost no effect on the reaction speed. 
B) increases the reaction speed by about 10%. 
C) increases the reaction speed by about 50%. 
D) approximately doubles the reaction speed. 
A) has almost no effect on the reaction speed. 
B) increases the reaction speed by about 10%. 
C) increases the reaction speed by about 50%. 
D) approximately doubles the reaction speed.

Question 9

A mole of any compound contains Avogadro's number of

Accepted Answer

A) atoms. 
B) ions. 
C) molecules. 
D) formula units. 
A) atoms. 
B) ions. 
C) molecules. 
D) formula units.

Question 10

In the electrolysis of molten NaCl, the substance liberated at the positive electrode is

Accepted Answer

A) Cl-. 
B) Cl2. 
C) Na+. 
D) Na. 
A) Cl-. 
B) Cl2. 
C) Na+. 
D) Na.

Question 11

Most chemical reactions

Accepted Answer

A) absorb energy. 
B) occur at rates that are independent of temperature. 
C) are reversible. 
D) produce precipitates. 
A) absorb energy. 
B) occur at rates that are independent of temperature. 
C) are reversible. 
D) produce precipitates.

Question 12

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. 
A) 19 percent. 
B) 35 percent. 
C) 40 percent. 
D) 81 percent.

Question 13

When 1 g of a metal is oxidized, the resulting oxide has a mass that is

Accepted Answer

A) less than 1 g. 
B) equal to 1 g. 
C) more than 1 g. 
D) Any of these choices could be correct, depending on the metal. 
A) less than 1 g. 
B) equal to 1 g. 
C) more than 1 g. 
D) Any of these choices could be correct, depending on the metal.

Question 14

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

Question 15

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

Accepted Answer

A) electrons. 
B) H+ ions. 
C) O2- ions. 
D) O2 molecules. 
A) electrons. 
B) H+ ions. 
C) O2- ions. 
D) O2 molecules.

Question 16

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. 
A) a lighted candle. 
B) the rusting of iron. 
C) the lighting of a match. 
D) a log burning in a fireplace.

Question 17

Chemical reactions in solution do not depend to any great extent upon

Accepted Answer

A) pressure. 
B) temperature. 
C) concentration. 
D) catalysts. 
A) pressure. 
B) temperature. 
C) concentration. 
D) catalysts.

Question 18

One mole of which of the following compounds contains the largest number of fluorine atoms?

Accepted Answer

A) HF 
B) SF2 
C) BF3 
D) XeF6 
A) HF 
B) SF2 
C) BF3 
D) XeF6

Question 19

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

Question 20

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

Accepted Answer

A) CO2 
B) SiO2 
C) BaSO4 
D) H2O 
A) CO2 
B) SiO2 
C) BaSO4 
D) H2O

The number of calcium atoms in 1 g of calcium is

The yield of the product C in the reversible reaction A + B C + energy can be increased by

The chief reason why reaction rates increase with temperature is that a rise in temperature increases the number of

If a certain reaction is endothermic, the reverse reaction

Ammonia gas dissolves in water and can react according to the equation NH₃ + H₂O NH₄⁺ OH^-.The amount of ammonium ion in solution will be increased by which one or more of the following?

Oxidation-reduction reactions are not involved in

The number of moles of Al needed to react with each mole of CuSO₄ in the reaction 2Al + 3CuSO₄ $\rarr$ 3 Cu + Al₂(SO₄)₃ is

For a reaction that takes place near room temperature, an increase of 10^$\circ$C

A mole of any compound contains Avogadro's number of

In the electrolysis of molten NaCl, the substance liberated at the positive electrode is

Most chemical reactions

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

When 1 g of a metal is oxidized, the resulting oxide has a mass that is

The decomposition of an unstable compound usually

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

An example of slow oxidation is

Chemical reactions in solution do not depend to any great extent upon

One mole of which of the following compounds contains the largest number of fluorine atoms?

The mass of Avogadro's number of silicon atoms is

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

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Exam 12: Chemical Reactions

The number of calcium atoms in 1 g of calcium is

The yield of the product C in the reversible reaction A + B C + energy can be increased by

The chief reason why reaction rates increase with temperature is that a rise in temperature increases the number of

If a certain reaction is endothermic, the reverse reaction

Ammonia gas dissolves in water and can react according to the equation NH3 + H2O NH4+ OH-.The amount of ammonium ion in solution will be increased by which one or more of the following?

Oxidation-reduction reactions are not involved in

The number of moles of Al needed to react with each mole of CuSO4 in the reaction 2Al + 3CuSO4 →\rarr→ 3 Cu + Al2(SO4)3 is

For a reaction that takes place near room temperature, an increase of 10 ∘\circ∘ C

A mole of any compound contains Avogadro's number of

In the electrolysis of molten NaCl, the substance liberated at the positive electrode is

Most chemical reactions

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

When 1 g of a metal is oxidized, the resulting oxide has a mass that is

The decomposition of an unstable compound usually

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

An example of slow oxidation is

Chemical reactions in solution do not depend to any great extent upon

One mole of which of the following compounds contains the largest number of fluorine atoms?

The mass of Avogadro's number of silicon atoms is

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

The Scientific Method

Motion

Energy

Energy and the Future

Matter and Heat

Electricity and Magnetism

Waves

The Nucleus

The Atom

The Periodic Law

Crystals, Ions, and Solutions

Organic Chemistry

Atmosphere and Hydrosphere

The Rock Cycle

The Evolving Earth

The Solar System

The Stars

Universe

Filters

Ammonia gas dissolves in water and can react according to the equation NH₃ + H₂O NH₄⁺ OH^-.The amount of ammonium ion in solution will be increased by which one or more of the following?

The number of moles of Al needed to react with each mole of CuSO₄ in the reaction 2Al + 3CuSO₄ $\rarr$ 3 Cu + Al₂(SO₄)₃ is

For a reaction that takes place near room temperature, an increase of 10^$\circ$C

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