Galvanic Cell Video Lessons

Concept

# Problem: Sketch the galvanic cells based on the following overall reactions. Show the direction of electron flow, and identify the cathode and anode. Give the overall balanced equation. Assume that all concentrations are 1.0 M and that all partial pressures are 1.0 atm.a. Cr3+ (aq) + Cl2 (g) ⇌ Cr2O72- (aq) + Cl - (aq)

###### FREE Expert Solution

We’re being asked to sketch a galvanic cell for the following reaction:

Cr3+ (aq) + Cl2 (g)  Cr2O72- (aq) + Cl - (aq)

Recall that a voltaic or galvanic cell is an electrochemical cell that is spontaneous and produces electricity

From the reaction, we can see that the oxidation state of Cr went from +3 (Cr3+) to +6 (Cr2O72-) which means it was oxidized or lost electrons

The anode (–) half-reaction is:

2 Cr3+(aq) + 7 H2O(l)  Cr2O72-(aq) + 14 H+(aq) + 6e-

6 e to the product side

The other half-reaction is then reduced or gained electrons

The cathode (+) half-reaction is:

Cl2(g) + 2 e  2 Cl-(aq)

2(–1) + 8(+1) + x = 0

2 e to the reactant side

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###### Problem Details

Sketch the galvanic cells based on the following overall reactions. Show the direction of electron flow, and identify the cathode and anode. Give the overall balanced equation. Assume that all concentrations are 1.0 M and that all partial pressures are 1.0 atm.

a. Cr3+ (aq) + Cl2 (g) ⇌ Cr2O72- (aq) + Cl - (aq)