Question
Question: Given that \(E_{H_{2}O|H_{2}|Pt}\)= 0 at 298 K. The pressure of H<sub>2</sub>(g) would be –...
Given that EH2O∣H2∣Pt= 0 at 298 K. The pressure of H2(g) would be –
A
10–7 bar
B
10–10bar
C
10–12 bar
D
10–14 bar
Answer
10–14 bar
Explanation
Solution
The cell reaction is : 2H+ + 2e → H2
Ecell = Eŗcell – 20.059 log [H+]2pH2
Eŗcell = 0, Ecell = 0
∴ pH2= [H+]2
In pure water, [H+] = 10–7 (M)
∴ pH2 = 10–14 bar.