Calculate the standard cell potential for the reaction: Cd(s) + Sn²⁺(aq) → Cd²⁺(aq) + Sn(s). Given the standard reduction potentials: E°(Cd²⁺/Cd) = -0.40 V and E°(Sn²⁺/Sn) = -0.14 V.

• A. -0.26 V
• B. -0.54 V
• C. 0.26 V
• D. 0.54 V

Answer: (A)

Verified step by step guidance

1. Identify the half-reactions involved in the overall cell reaction. The oxidation half-reaction is Cd(s) → Cd²⁺(aq) + 2e⁻, and the reduction half-reaction is Sn²⁺(aq) + 2e⁻ → Sn(s).
2. Determine the standard reduction potentials for each half-reaction. The given values are E°(Cd²⁺/Cd) = -0.40 V and E°(Sn²⁺/Sn) = -0.14 V.
3. Recognize that the standard cell potential (E°cell) is calculated using the formula: E°cell = E°(reduction) - E°(oxidation).
4. Since the reduction potential for Sn²⁺/Sn is given, use it directly as E°(reduction). For the oxidation potential of Cd, reverse the sign of the given reduction potential: E°(oxidation) = -(-0.40 V) = 0.40 V.
5. Substitute the values into the formula: E°cell = E°(Sn²⁺/Sn) - E°(Cd²⁺/Cd) = -0.14 V - 0.40 V. Calculate the result to find the standard cell potential.