Redox Reactions And Electrochemistry Ques 717
Question: The reduction potential of hydrogen half-cell will be negative if
Options:
A) $ p(H_2)=2,atm,and,[{H^{+}}]=2.0M $
B) $ p(H_2)=1,atm,and,[{H^{+}}]=2.0M $
C) $ p(H_2)=1,atm,and,[{H^{+}}]=1.0M $
D) $ p(H_2)=2,atm,and,[{H^{+}}]=1.0M $
Show Answer
Answer:
Correct Answer: D
Solution:
[d] For $ {H^{+}}(aq)+{e^{-}}\to (1/2)H_2(g), $ we have $ E=-\frac{RT}{F}\ln \frac{{{( pH_2/atm )}^{1/2}}}{( [{H^{+}}]/M )} $ For E to be negative, the ratio $ \frac{{{( pH_2/atm )}^{1/2}}}{( [{H^{+}}]/M )} $ should be greater than 1. Only the choice ([d] produces this result.
