Exam 3 True/False Practice

Question 1

Lewis bases are electron pair donors

Answer 1

True

Question 2

In Zn2+(aq) + 4 NH3(aq) Zn(NH3)42+(aq), Zn2+ acts as a Lewis acid.

Answer 2

True

Question 3

In (CH3)3N(g) + BF3(g) (CH3)3NBF3(s), (CH3)3N acts as a Lewis base.

Answer 3

True

Question 4

Kinetics involves the rates of reactions and the energy of intermediate states; thermodynamics involves the relative chemical potentials of reactants and products

Answer 4

True

Question 5

spontaneous process occurs without ongoing outside intervention

Answer 5

True

Question 6

Nonspontaneous processes can occur if external energy is supplied or if the process is coupled with a highly spontaneous process

Answer 6

True

Question 7

Spontaneous reactions always have a fast rate

Answer 7

False

Question 8

catalyst can make a nonspontaneous process spontaneous

Answer 8

False

Question 9

All spontaneous processes increase the entropy of the universe

Answer 9

True

Question 10

Entropy increases as energy is more concentrated

Answer 10

False

Question 11

The expansion of an ideal gas into a vacuum is a spontaneous process because it increases the number of energetically equivalent ways to arrange the gas molecules in the system

Answer 11

True

Question 12

The units of entropy are J/K

Answer 12

True

Question 13

If ΔS is negative and ΔH is positive, the process is spontaneous at low temperatures

Answer 13

False

Question 14

If ΔS is positive for an exothermic reaction, it is spontaneous for all temperatures

Answer 14

True

Question 15

If ΔS is positive for an endothermic reaction, it is spontaneous at high temperatures

Answer 15

True

Question 16

If ΔS is negative and ΔH is negative, the process is nonspontaneous for all temperatures

Answer 16

False

Question 17

Reduction is gain of electrons

Answer 17

True

Question 18

In 2 H2(g) + O2(g) –> 2 H2O(g), H2(g) is the reducing agent

Answer 18

True

Question 19

The oxidation number of O in O3(g) is –2.

Answer 19

False

Question 20

The oxidation number of O in H2O2 is –2.

Answer 20

False

Question 21

In 2 Na(s) + I2(g) –> 2 NaI(s), Na is reduced

Answer 21

False

Question 22

The oxidation number of Mn in MnO4– is +7.

Answer 22

True

Question 23

The oxidation number of Fe2+ is +2.

Answer 23

True

Question 24

In an electrolytic cell, electric current drives an otherwise nonspontaneous redox reaction

Answer 24

True

Question 25

In an electrolytic cell, oxidation occurs at the cathode

Answer 25

False

Question 26

In an electrolytic cell, electrons are drawn away from the anode, which is connected to the positive terminal of an external power source

Answer 26

True

Question 27

In the electrolysis of a pure molten salt, the anion is oxidized and the cation is reduced

Answer 27

True

Question 28

Unlike a battery, a fuel cell requires a constant supply of reactants

Answer 28

True