# Exercise 4 | Electrochemistry

Given that [Al3+] = 1.00 x 10-2 M, what is the reduction potential for the following half-reaction:

Al3+ (aq) + 3 e- → Al (s)?

Data: E0red [Al3+] = - 1.66 V at 25°C

Nernst equation:

At 25°C:

Ered = E0red$\frac{\mathrm{RT}}{{\mathrm{\nu }}_{\mathrm{e}}\mathrm{F}}$ x ln Q = E0red$\frac{0.02570}{{\mathrm{\nu }}_{\mathrm{e}}}$ x ln Q

Ered = reduction potential (in V)
E0red = -1.66V
νe = stoichiometric coefficient of the electrons = 3
Q = reaction quotient = 1 / [Al3+]

Ered = E0red$\frac{0.02570}{{\mathrm{\nu }}_{\mathrm{e}}}$ x ln Q

Ered = - 1.66 + $\frac{0.02570}{3}$ x ln 0.200

Ered = - 1.70 V