Electrochemistry Review

Given the following cell:

Zn | Zn²⁺ || Sn²⁺ | Sn

in order to increase the voltage, one could

• increase [Zn²⁺].

• increase [Sn²⁺].

• use more Zn.

• use more Sn.

Tags

NGSS.HS-PS1-5

Which one of the following reactions will not occur spontaneously?

• Mg_(s) + 2Ag⁺_(aq) ⟶ Mg²⁺_(aq) + 2Ag_(s)

• Hg²⁺_(aq) + Zn_(s) ⟶ Hg_(l) + Zn²⁺_(aq)

• Cu²⁺_(aq) + Zn_(s) ⟶ Cu_(s)+ Zn²⁺_(aq)

• 2Ag_(s) + Ni²⁺_(aq) ⟶ 2Ag⁺_(aq) + Ni_(s)

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What is the oxidation number of manganese is MnO₄^-

• +2

• +4

• +7

• +8

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

When solid iron is oxidized to Fe²⁺_(aq) by CuNO₃ at 25°C, the standard cell potential is 0.927 V. What is ΔG°?

• -89 kJ

• -179 kJ

• +179 kJ

• +89 kJ

Tags

NGSS.HS-PS1-4

Mg_(s) + 2H⁺_(aq) ⟶ Mg²⁺_(aq) + H_2(g)

The standard potential for the reaction above is 2.357 V.

What is true of the cell potential when [H⁺] = 2.0 M, [Mg²⁺] = 0.0050 M, and P_H2 = 0.40 atm?

• E < 2.357 V

• E = 2.357 V

• E > 2.357 V

Tags

NGSS.HS-PS1-4

The standard reduction potential for

Mg²⁺_(aq) + 2e^- ⟶ Mg_(s)

is -2.37V. What is the reduction potential for

2Mg²⁺_(aq) + 4e^- ⟶ 2Mg_(s)?

• -4.74 V

• -2.37 V

• +2.37 V

• +4.74 V

What is the voltage of the electrochemical cell when the reaction below reaches equilibrium?

Mg_(s) + 2Fe³⁺_(aq) ⟶ Mg²⁺_(aq) + 2Fe²⁺_(aq)

• +3.14 V

• +1.60 V

• +0.83 V

• 0.00 V

Tags

NGSS.HS-PS3-1

A 50–milliliter sample of a 2-molar CuSO₄ solution is added to the left beaker. What happens?

• Voltage increases.

• Voltage decreases.

• No change in voltage occurs.

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5

As the reaction progress, in which direction do the NO₃^- anions flow in the salt bridge?

• to the right into the reduction half-cell

• to the left into the oxidation half-cell

• nowhere

As the reaction progresses toward completion, which of the following will occur? (Check all that apply.)

• The copper anode will increase in mass.

• The zinc cathode will increase in mass.

• [Cu²⁺] in the oxidation half-cell will increase.

• [Zn²⁺] in the reduction half-cell will increase.

Tags

NGSS.HS-PS2-5