Question

The potential of a hydrogen electrode at PH = 10 is

Options

• + 59 V

• 0.00 V

• – 0.59 V

• 2.5 V

Answer 1

– 0.59 V

Explanation:

pH = 10

[H⁺] = 10^–pH

[H⁺] = 10^–10 M

2H⁺ + 2e^– → H₂

E_cell = `E_(cell)^circ - 0.059/n  log  (P_(H_2))/[H^+]^2`

E_cell = `0.0 V - 0.059/2  log  (1  atm)/[10^-10]^2`

E_cell = `- 0.059/2  log  10^20`

E_cell = `- (0.059 xx 20)/2`

E_cell = – 0.59 V

The potential of a hydrogen electrode at pH = 10 is − 0.59V.