Redox Reactions And Electrochemistry Ques 725
Question: A cell diagram shown below contains one litre of Buffer solution $ HA(pK_{a}=8) $ and NaA in both compartment. What is the cell emf-
Options:
A) 0.81 V
B) 0.071 V
C) 0.0591 V
D) 1.182 V
Show Answer
Answer:
Correct Answer: C
Solution:
[c] $ E _{cell}=\frac{0.0591}{1}\log \frac{{{[{H^{+}}]} _{RHS}}}{{{[{H^{+}}]} _{LHS}}} $
$ E _{cell}=0.0591[pH _{LHS}-pH _{RHS}] $
$ pH _{LHS}pK _{a}+\log \frac{[{A^{-}}]}{[HA]} $
$ =8+\log \frac{1}{0.1}=9 $ $ pH _{RHS}=8 $
$ E _{cell}=0.0591(9-8)=0.0591V $
