NEET Solved Paper 2016 Question 30
Question: The pressure of $ {H_2} $ required to make the potential of $ {H_2}- $ electrode zero in pure water at 298 K is :-
Options:
A) $ 10^{14}\text{ atm} $
B) $ 10^{12}\text{ atm} $
C) $ {10^{-10}}atm $
D) $ {10^{-4}}atm $
Show Answer
Answer:
Correct Answer: A
Solution:
$ 2{H^{+}}(aq)+2{e^{-}}\to H _2(g) $
$ \therefore $ $ E=E^{o}-\frac{0.0591}{2}\log \frac{{P _{H _2}}}{{{[{H^{+}}]}^{2}}} $ $ 0=0-0.0295\log \frac{{P _{H _2}}}{{{[{10^{-7}}]}^{2}}} $ $ \frac{{P _{H _2}}}{{{({10^{-7}})}^{2}}}=1 $ $ {P _{H _2}}={10^{-4}}\ atm $
