GKFix MCQ Question

Which of the following reactions requires acidic conditions for optimal performance?

• A. Zn2+ + 2e– → Zn(s)
• B. 2H2O + 2e– → H2(g) + 2OH–
• C. Cr2O72– + 14H+ + 6e– → 2Cr3+ + 7H2O
• D. Na+ + e– → Na(s)