The cell potential for the following cell
Pt|H₂(g)|H⁺(aq)||Cu²⁺(0.01 M)|Cu(s)
is 0.576 V at 298 K. The pH of the solution is ______. (Nearest integer)
Pt|H₂(g)|H⁺(aq)||Cu²⁺(0.01 M)|Cu(s)
is 0.576 V at 298 K. The pH of the solution is ______. (Nearest integer)
Answer: 5
Solution
Cell reaction: Cu²⁺ + H₂ → 2H⁺ + Cu. E°cell = E°(Cu²⁺/Cu) = 0.34 V. Using Nernst equation: Ecell = E°cell - (0.06/2) log([H⁺]²/[Cu²⁺]). Substituting: 0.576 = 0.34 - 0.03 log([H⁺]²/0.01). Solving: 0.236 = -0.03 log([H⁺]²/0.01). -7.87 = log([H⁺]²) + 2. log([H⁺]²) = -9.87. 2log[H⁺] = -9.87. log[H⁺] = -4.935. pH ≈ 5.
JEE Main · 2022 · 24 Jun 2022 · Shift 1 · Integer answer