At 25ºC, the standard emf of cell having reactions involving two electron change is found to be 0.295 V. The equilibrium constant of the reaction is:
Correct answer: C. 1010
- A. 29.5 x 10^-2
- B. 10
- C. 1010
- D. 29.5 x 10^10
Explanation
The Nernst equation, when simplified for a standard cell reaction at 25ºC, relates the standard emf (E0) to the equilibrium constant (K) as follows:E0 = (RT/nF) ln KAt 25ºC, this simplifies to E0 = (0.0591/n) log K, where n is the number of moles of electrons exchanged. With E0 = 0.295 V and n = 2, we solve:0.295 = (0.0591/2) log Klog K = (0.295 * 2) / 0.0591 ≈ 10Thus, K ≈ 1010, making option C correct. The other options misinterpret or miscalculate this relationship.
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