Question

For the following concentration cell, to be spontaneous $Pt \left( H _{2}\right) P_{1}$ atm. $\mid HCl Pt \left( H _{2}\right) P_{2}\, atm$. Which of the following is correct?

• A. $P_{1}=P_{2}$
• B. $P_{1} < P_{2}$
• C. $P_{1} > P_{2}$
• D. Can't be predicted

Answer 1

Answer: (C)

$Pt \left( H _{2}\right) P _{1}$ atm. $\mid Pt \left( H _{2}\right) P _{2}\, atm$.

For spontaneous reaction, $E_{ cell }$ should be positive so $P_{1}>P_{2}$

$E_{ cell }=\frac{0.059}{2} \log \frac{P_{1}}{P_{2}}$

Also, if $P_{1}>P_{2}$ oxidation occurs at L.H.S. electrode and reduction occurs at R.H.S. electrode.