How does pH affect the Nernst equation?
1 Answer
pH doesn't affect the Nernst equation.
But the Nernst equation predicts the cell potential of reactions that depend on pH.
If H⁺ is involved in the cell reaction, then the value of
For the half-reaction, 2H⁺ + 2e⁻ → H₂,
According to the Nernst equation,
If
EXAMPLE
Calculate the cell potential for the following cell as a function of pH.
Cu²⁺(1 mol/L) + H₂(1 atm) → Cu(s) + 2H⁺(aq)
Solution
Cu²⁺ + 2e⁻ → Cu;
H₂ → 2H⁺ + 2e⁻;
Cu²⁺ + H₂ → Cu + 2H⁺;
