Question 1

The mass of 1 mole of oxygen, O2, is 32 g.The atomic mass of oxygen is

Accepted Answer

A) 16 u. 
B) 16 g. 
C) 32 u. 
D) 32 g. 
A) 16 u. 
B) 16 g. 
C) 32 u. 
D) 32 g.

Question 2

A chemical equilibrium occurs when the

Accepted Answer

A) mass of the products equals the mass of the reactants. 
B) number of molecules of the products equals the number of molecules of the reactants. 
C) concentration of the products equals the concentration of the reactants. 
D) speed of the forward reaction equals the speed of the reverse reaction. 
A) mass of the products equals the mass of the reactants. 
B) number of molecules of the products equals the number of molecules of the reactants. 
C) concentration of the products equals the concentration of the reactants. 
D) speed of the forward reaction equals the speed of the reverse reaction.

Question 3

An example of an exothermic process is the

Accepted Answer

A) dissociation of a salt in water solution. 
B) neutralization of an acid by a base. 
C) electrolysis of water. 
D) melting of ice. 
A) dissociation of a salt in water solution. 
B) neutralization of an acid by a base. 
C) electrolysis of water. 
D) melting of ice.

Question 4

The scientist whose experiments showed that tin, upon heating, combined with a gas from the air was

Accepted Answer

A) Priestley. 
B) Stahl. 
C) Lavoisier. 
D) Becher. 
A) Priestley. 
B) Stahl. 
C) Lavoisier. 
D) Becher.

Question 5

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 6

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 7

When a hydrogen fuel cell produces an electric current,

Accepted Answer

A) it must be recharged periodically. 
B) it must be heated. 
C) it must have hydrogen added to it continuously. 
D) it gives off carbon dioxide. 
A) it must be recharged periodically. 
B) it must be heated. 
C) it must have hydrogen added to it continuously. 
D) it gives off carbon dioxide.

Question 8

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 g of sulfur is

Accepted Answer

A) 32. 
B) 1.9 * 1022. 
C) 6 * 1023. 
D) 1.9 * 1025. 
A) 32. 
B) 1.9 * 1022. 
C) 6 * 1023. 
D) 1.9 * 1025.

Question 9

Of the following battery types, the one with the highest energy density is

Accepted Answer

A) lead-acid. 
B) lithium-ion. 
C) nickel-cadmium. 
D) nickel-metal-hydride. 
A) lead-acid. 
B) lithium-ion. 
C) nickel-cadmium. 
D) nickel-metal-hydride.

Question 10

Chemical reactions that give off energy are called

Accepted Answer

A) endothermic. 
B) exothermic. 
C) activated. 
D) oxidation-reduction. 
A) endothermic. 
B) exothermic. 
C) activated. 
D) oxidation-reduction.

Question 11

When a metal is oxidized, the resulting oxide

Accepted Answer

A) has less mass than the original metal. 
B) has the same mass as the original metal. 
C) has more mass than the original metal. 
D) Any of these choices could be correct, depending on the metal. 
A) has less mass than the original metal. 
B) has the same mass as the original metal. 
C) has more mass than the original metal. 
D) Any of these choices could be correct, depending on the metal.

Question 12

The time needed for a strong acid to neutralize a strong base in solution

Accepted Answer

A) decreases with temperature. 
B) increases with temperature. 
C) is virtually independent of temperature. 
D) Any of these choices could be correct, depending on the particular acid and base. 
A) decreases with temperature. 
B) increases with temperature. 
C) is virtually independent of temperature. 
D) Any of these choices could be correct, depending on the particular acid and base.

Question 13

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 14

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 15

The yield of the product C in the reversible reaction A + B   C + energy will decrease if

Accepted Answer

A) the temperature decreases. 
B) the temperature increases. 
C) the surface area of the substances increases. 
D) the catalyst is changed appropriately. 
A) the temperature decreases. 
B) the temperature increases. 
C) the surface area of the substances increases. 
D) the catalyst is changed appropriately.

Question 16

At ordinary temperatures, the temperature increase needed to double the rate of many common chemical reactions is

Accepted Answer

A) 1$\circ$C. 
B) 10$\circ$C. 
C) 50$\circ$C. 
D) 100$\circ$C. 
A) 1$\circ$C. 
B) 10$\circ$C. 
C) 50$\circ$C. 
D) 100$\circ$C.

Question 17

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 18

When sodium and chlorine react to form sodium chloride (NaCl), 411 kJ per mole of NaCl is given off.To break up 1 mole of NaCl into sodium and chlorine requires

Accepted Answer

A) less than 411 kJ. 
B) 411 kJ. 
C) more than 411 kJ. 
D) any of the above, depending on the circumstances. 
A) less than 411 kJ. 
B) 411 kJ. 
C) more than 411 kJ. 
D) any of the above, depending on the circumstances.

Question 19

Reaction rates increase with temperature mainly because a rise in temperature increases

Accepted Answer

A) the number of ions. 
B) the number of polar molecules. 
C) the number of activated molecules. 
D) the average length of time between molecular collision. 
A) the number of ions. 
B) the number of polar molecules. 
C) the number of activated molecules. 
D) the average length of time between molecular collision.

Question 20

When a gas reaction involves an increase in the number of molecules present, the yield can be increased by

Accepted Answer

A) increasing the pressure. 
B) decreasing the pressure. 
C) increasing the temperature. 
D) decreasing the temperature. 
A) increasing the pressure. 
B) decreasing the pressure. 
C) increasing the temperature. 
D) decreasing the temperature.

The mass of 1 mole of oxygen, O₂, is 32 g.The atomic mass of oxygen is

A chemical equilibrium occurs when the

An example of an exothermic process is the

The scientist whose experiments showed that tin, upon heating, combined with a gas from the air was

Most chemical reactions

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

When a hydrogen fuel cell produces an electric current,

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 g of sulfur is

Of the following battery types, the one with the highest energy density is

Chemical reactions that give off energy are called

When a metal is oxidized, the resulting oxide

The time needed for a strong acid to neutralize a strong base in solution

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

If a certain reaction is endothermic, the reverse reaction

The yield of the product C in the reversible reaction A + B C + energy will decrease if

At ordinary temperatures, the temperature increase needed to double the rate of many common chemical reactions is

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

When sodium and chlorine react to form sodium chloride (NaCl), 411 kJ per mole of NaCl is given off.To break up 1 mole of NaCl into sodium and chlorine requires

Reaction rates increase with temperature mainly because a rise in temperature increases

When a gas reaction involves an increase in the number of molecules present, the yield can be increased by

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Exam 12: Chemical Reactions

The mass of 1 mole of oxygen, O2, is 32 g.The atomic mass of oxygen is

A chemical equilibrium occurs when the

An example of an exothermic process is the

The scientist whose experiments showed that tin, upon heating, combined with a gas from the air was

Most chemical reactions

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

When a hydrogen fuel cell produces an electric current,

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 g of sulfur is

Of the following battery types, the one with the highest energy density is

Chemical reactions that give off energy are called

When a metal is oxidized, the resulting oxide

The time needed for a strong acid to neutralize a strong base in solution

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

If a certain reaction is endothermic, the reverse reaction

The yield of the product C in the reversible reaction A + B C + energy will decrease if

At ordinary temperatures, the temperature increase needed to double the rate of many common chemical reactions is

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

When sodium and chlorine react to form sodium chloride (NaCl), 411 kJ per mole of NaCl is given off.To break up 1 mole of NaCl into sodium and chlorine requires

Reaction rates increase with temperature mainly because a rise in temperature increases

When a gas reaction involves an increase in the number of molecules present, the yield can be increased by

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

The Universe

Filters

The mass of 1 mole of oxygen, O₂, is 32 g.The atomic mass of oxygen is

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 g of sulfur is