Free Printable CHM3101 Electrochemistry

1.

Which of the following statements accurately describes the difference between galvanic and electrolytic cells?

a)

The anode is the negative terminal for a Galvanic cell because the anode is the source of the electrons where oxidation occurs.

b)

The flow of electrons goes from the anode to the cathode for galvanic cells.

c)

Oxidation occurs at the negative terminal, and reduction occurs at the positive terminal for an electrolytic cell.

2.

Based on Standard Reduction Potential at 25℃ given below, calculate the standard cell potential, E°cell.

$Mg_{\left(aq\right)}^{2+}+2e^-\rightarrow Mg_{\left(s\right)}$ ; E°= -2.37V
$Al_{\left(aq\right)}^{3+}+3e^-\rightarrow Al_{\left(s\right)}$ ; E°= -1.66V

a)

- 0.71V

b)

- 4.03V

c)

+0.71V

d)

+4.03V

3.

Which of the following statements accurately describes the Nernst equation shown below?

a)

At equilibrium, E_cell calculates to a value of 0 and the battery is considered dead because Q becomes K_eq and K_eq has a value of 0.

b)

Increasing the concentration of the reactants will increase the value of E_cell.

c)

This equation is used to figure out the standard cell potential at any concentration, partial pressure or temperature.

d)

At standard conditions, E_cell = E°_cell because all the concentrations are 1 M at an ambient temperature of 273 K.

4.

What is equilibrium constant, K if E°cell=+0.71V at 298 K.

Mg_{\left(aq\right)}^{2+}+2e^-\ \rightarrow Mg_{\left(s\right)}\ \ \ \ \ \left(\times3\right)

Al_{\left(aq\right)}^{3+}+3e^-\rightarrow Al_{\left(s\right)}\ \ \ (\times2)

Overall eq:

3Mg_{\left(s\right)}+2Al_{\left(aq\right)}^{3+}\rightarrow3Mg_{\left(aq\right)}^{2+}+2Al_{\left(s\right)}

(F = 96485 C/ mol

\overline{e}

; R= 8.31 J/(mol.K))

a)

$1.212\times10^{72}$

b)

$-1.212\times10^{72}$

c)

$1.101\times10^{36}$

d)

$-1.101\times10^{36}$

5.

Are dry cell batteries one example of galvanic cells?

a)

True

b)

False

6.

In an electrolyte concentration cell, a half-cell with electrolyte of _________ concentration will be at the __________ side.

To answer this question, you can answer more than one.

a)

lower, cathode

b)

lower, anode

c)

higher, cathode

d)

higher, anode

7.

To eliminate liquid junction potential is by placing the salt bridge in an electrochemical cell?

a)

True

b)

False

8.

Cell potential is proportional to the slope of the Gibbs energy with respect to the extent of the reaction.

a)

True

b)

False

9.

E° values are dependent on the stoichiometric coefficients for the half-reaction, and, most importantly, the coefficients used to produce a balanced overall reaction do not affect the value of the cell potential.

a)

True

b)

False

10.

Shown below is the schematic diagram of a zinc-carbon dry cell. Is it correct about the following half reactions?

Anode half-reaction: $Zn_{\left(s\right)}→Zn_{\left(aq\right)}^{2+}+2e^-$
Cathode half-reaction: $2MnO_{2\left(s\right)}+2NH_{4\left(aq\right)}^-+2e^-→Mn_2O_{3\left(s\right)}+2NH_{3\left(aq\right)}+H_2O_{\left(l\right)}$

a)

No

b)

Yes

CHM3101 Electrochemistry

Total questions: 10

Worksheet time: 6mins

Similar Resources on Wayground