Question

The cell reaction for the given cell is spontaneous if :
$\underset{P_1}{PtC{l}_2}|\underset{1M}{C{l}^{-}}||\underset{1M}{C{l}^{-}}|\underset{P_2}{PtC{l}_2}$

• A. $P_1>P_2$
• B. $P_1<P_2$
• C. $P_1=P_2$
• D. $P_2=1atm$

Answer 1

The correct option is B $P_1<P_2$

$\underset{P_1}{PtC{l}_2}|\underset{1M}{C{l}^{-}}||\underset{1M}{C{l}^{-}}|\underset{P_2}{PtC{l}_2}$

Reaction of cell:

LHS $2C{l}^{-}\to \underset{P_1}{C{l}_2}+2e$

RHS $\underset{P_2}{C{l}_2}+2e\to 2C{l}^{-}$

According to Nernst equation:

$E=E^o-0.0591logQ/n$

As conc. of chloride is same in both side so

$E_{cell}=\frac{0.059}{2}log\frac{P_{C{l}_2}RHS}{P_{C{l}_2}LHS}$

If reaction is spontaneous then $E>0$ and

$E_{cell}=+ve$ if $P_2>P_1$