Redox Reactions And Electrochemistry Ques 610
Question: The reduction potential (in volt) of a hydrogen electrode set up with a $ 2\times {10^{-2}}M $ aqueous solution of a weak mono basic acid $ (K_{a}=5\times {10^{-5}}) $ at one atmosphere and $ 25{}^\circ C $ is
Options:
A) +0.09
B) +0.18
C) $ -0.09 $
D) $ -0.18 $
Show Answer
Answer:
Correct Answer: D
Solution:
[d] $ 2{H^{+}}+2{e^{-}}\xrightarrow{{}}H_2 $ $ E_{cell}=0.06,log[{H^{+}}]=0.06\times log\sqrt{K_{a}C} $ $ =0.06\times log{10^{-3}}=-0.18V $
