Redox Reactions And Electrochemistry Ques 184
Question: For a cell reaction involving a two-electron change, the standard emf of the cell is found to be 0.295 V at $ 25^{o}C $ . The equilibrium constant of the reaction at $ 25^{o}C $ will be [Roorkee 1999; AIEEE 2003; CBSE PMT 2004]
Options:
A) $ 1\times {10^{-10}} $
B) $ 29.5\times {10^{-2}} $
C) 10
D) $ 1\times 10^{10} $
Show Answer
Answer:
Correct Answer: D
Solution:
$ \Delta G=-nFE^{o} $ $ \Delta G=-2.303RT,\log ,K $ ;
$ nFE^{o}=2.303RT,\log ,K $
$ \log K=\frac{nFE^{o}}{2.303RT}=\frac{2\times 96500\times 0.295}{2.303\times 8.314\times 298} $
$ \log K=9.97=K=1\times 10^{10} $ .
