Chapter 19 Practice Test

Question 1

What is the common oxidation number for oxygen in a compound?

Answer 1

-2

Question 2

What is the oxidation number for nitrogen in Cu(NO3 )2 for the following reaction?

Answer 2

+5

Question 3

Which of the following is the balanced equation for the reaction between the permanganate ion and chloride ion in an acidic solution?
MnO4- + Cl- -> Mn2+ + Cl2

Answer 3

2MnO4- + 10Cl- + 16 H+ -> 2Mn2+ + 5Cl2 + 8H2O

Question 4

In the diagram of an galvanic cell, which is the anode?

Answer 4

A

Question 5

In the following reaction, which half reaction would take place at the anode?

Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

Answer 5

Zn(s) → Zn2+ (aq) + 2e−

Question 6

In the diagram of an electrolytic cell, where is oxidation taking place?

Answer 6

A

Question 7

One compartment of a galvanic cell contains a zinc strip in a solution of Zn(NO3 )2. The other compartment contains a nickel strip in a solution of NiCl2. Which reaction occurs at the anode and which reaction occurs at the cathode?? In this cell, the standard reduction potential for zinc is −0.76 V and the standard reduction potential for nickel is −0.23 V

Answer 7

Anode Reaction: Zn -> Zn2+ + 2e-

Cathode Reaction: Ni2+ + 2e- -> Ni

Question 8

Which of the following can be done to make a cell with a higher EMF?

Answer 8

Use different metals

Question 9

Which unit is used to measure electromotive force(EMF)?

Answer 9

volts

Question 10

The standard potential of the tin ion (Sn2+) is -0.14 V

Sn2+(aq) + 2e- -> Sn(s)

What is the standard oxidation potential of the tine (Sn(s))?

Answer 10

+0.14 V

Question 11

Which of the following species is the strongest oxidizing agent?

Answer 11

Reduction half-reaction:
Au3+ + 3e−
Standard reduction potential:
+1.42 V

Question 12

Study the series of the standard aqueous electrode potentials at 25°C. Which is the strongest reducing agent in the group?

Answer 12

Lithium

Question 13

Using the table below, place the following in order of decreasing strength as oxidizing agents:

Fe2+, ClO2, F2, AgCl

Answer 13

F2 > ClO2 > AgCl > Fe2+

Question 14

Calculate the standard Gibbs free energy change in J / mol at 25°C for the following reaction:

3Sn4+ + 2Cr -> 3Sn2+ + 2Cr3+

Answer 14

−5.2 × 10^5 J / mol

Question 15

Calculate the equilibrium constant for the following reaction at 25°C, given that
E°cell = +0.99 V

3Cu(s) + Cr2O72-(aq) + 14H+(aq) –> 3Cu2+(aq) + 2Cr3+(aq) + 7H2O(l)

Answer 15

2.18 × 10^100

Question 16

How many half-reactions occur when a car battery discharges?

Answer 16

Two

Question 17

When does equilibrium occur in a battery?

Answer 17

Ecell = 0.

Question 18

What is the acid found in a lead-acid (storage) battery?

Answer 18

Sulfuric acid

Question 19

Which acid-base reaction occurs in a Leclanché cell?

Answer 19

NH4+ reacting with OH −

Question 20

Under anaerobic conditions, which of the following can oxidize iron?

Answer 20

H2O

Question 21

Which reaction best represents the formation of rust?

Answer 21

2Fe(OH)3(s) -> Fe2O3 * H2O(s) + 2H2O(l)

Question 22

Which of the following is the product of reduction in an electrolytic cell with molten NaCl?

Answer 22

Na

Question 23

In the diagram of an electrolytic cell, which is the anode?

Answer 23

A

Question 24

Consider the electrolytic process below

Cu2+(Aq) + 2e- -> Cu(s)

How many grams of copper are produced when a current of 10.0 amps is passed for 0.5 hours through a solution containing copper (II) ions?

Answer 24

5.94 g

Question 25

Use the table of standard reduction potentials to calculate the Ecell for the following reaction in a galvanic cell:

Zn(s) + Cu2+(aq) -> Zn2+(aq) + Cu(s)

Answer 25

+1.10 V