The number of incorrect statements from the f | vedclass

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(B) Statement $A$ is incorrect. The electrical work that a reaction can perform at constant pressure and temperature is equal to the decrease in Gibbs

Vedclass · Accepted Answer

$2$

Vedclass · Answer

(B) Statement $A$ is incorrect. The electrical work that a reaction can perform at constant pressure and temperature is equal to the decrease in Gibbs energy,i.e.,$W_{elec} = -\Delta_{r}G$. The statement says it is equal to $\Delta_{r}G$,which is incorrect.Statement $B$ is incorrect. $E_{cell}^0$ is the standard cell potential,which is defined at standard conditions ($1 \ bar$ pressure,$1 \ M$ concentration,$298 \ K$). It is a constant value for a given reaction and does not depend on the actual pressure of the system.Statement $C$ is correct. From the relation $\Delta_{r}G^0 = -nFE_{cell}^0$ and $\Delta_{r}G^0 = \Delta_{r}H^0 - T\Delta_{r}S^0$,we derive $\left(\frac{\partial \Delta_{r}G^0}{\partial T}\right)_P = -\Delta_{r}S^0$. Substituting $\Delta_{r}G^0$,we get $-nF \frac{dE_{cell}^0}{dT} = -\Delta_{r}S^0$,which simplifies to $\frac{dE_{cell}^0}{dT} = \frac{\Delta_{r}S^0}{nF}$.Statement $D$ is correct. $A$ cell operates reversibly when the external opposing potential is equal to the cell potential,resulting in zero net current flow.Thus,there are $2$ incorrect statements ($A$ and $B$).

Similar Questions

Given below are the half-cell reactions:
$Mn^{2+} + 2e^{-} \rightarrow Mn; E^{o} = -1.18 \ V$
$2(Mn^{3+} + e^{-} \rightarrow Mn^{2+}); E^{o} = +1.51 \ V$
The $E^{o}$ for $3Mn^{2+} \rightarrow Mn + 2Mn^{3+}$ will be:

Which of the following statements is wrong?

$A$ hydrogen electrode is immersed in a solution with $pH = 0$ $(HCl)$. By how much will the potential (reduction) change if an equivalent amount of $NaOH$ is added to the solution? (Take $pH_2 = 1 \ atm$,$T = 298 \ K$).

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