Physical Chemistry Answers

It requires ________ seconds to produce 1.0 g of silver metal by the electrolysis of a AgNO3 solution using a current of 30 amps.
30
60
3.2 × 103
2.7 × 104
3.7 × 10-5

The oxidising strength of Cr2O72-
is greatest in a solution of pH
1.0
3.0
7.0
10.0
13.0

Consider the following standard electrode potentials

Ag+ + e- = Ag, Eo = 0.80 V

Mn2+ + 2e- = Mn, Eo = -1.18 V


for the standard cell

Mn|Mn2+(aq)||Ag+(aq)|Ag


Which of the following statements are true?

1. The cell voltage will be 1.98 V.

2. One half-cell reaction is Mn = Mn2+ + 2e-
.

3. The overall cell potential will decrease with
time.

1 only
2 only
3 only
1 and 2 only
1, 2, and 3

For a certain oxidation-reduction reaction, Eo is
positive. This means that

ΔGo is negative and
K is less than 1.

ΔGo is negative and
K is greater than 1.

ΔGo is zero and K
is greater than 1.

ΔGo is positive and
K is greater than 1.

ΔGo is positive and
K is less than 1.

According to a table of standard reduction potentials, what is the best reducing agent among the following species?
Pb
Mg2+
Ag+
Ag
H2

For the reaction Cl2(g) + 2Fe2+(aq) ⇌ 2Fe3+(aq) + 2Cl-(aq) the value of Eo is 0.59 V.

The value of Eo for Fe3+(aq) + Cl-(aq) ⇌ 1/2 Cl2(g) + Fe2+(aq) is
-1.18 V
-0.59 V
-0.30 V
0.30 V
0.59 V

The more ________ the value of E°red, the greater the driving force for reduction.
negative
extensive
positive
exothermic
endothermic

Use standard reduction tables to determine which of the following species will convert Cd2+ to Cd
Fe3+
Pb2+
Zn
Co2+
Sn

Which of the following species will oxidize Ni but not Cu?
Zn2+
Mg
Pb2+
O2
Br-

A cell with the potential of 0.74 V has the cell reaction

2Cr + 6H+ ⇌ 2Cr3+ + 3H2


If the concentrations of the ions were 1.0 molar and the pressure of H2 were 1.0 atmosphere, then the Eo for the half-reaction

Cr3+ + 3e- ⇌ Cr


would be

-0.74 V
-0.37 V
0.25 V
0.37 V
0.74 V.