Question

For the cell reaction,

$C{u}_{\left(aq\right)}^{2+}\left(c_2\right)+Z{n}_{\left(s\right)}\to Z{n}_{\left(aq\right)}^{2+}\left(c_1\right)+C{u}_{\left(s\right)}$,

the change in free energy $\left(\Delta G\right)$ at a given temperature is a function of:

• A. In $c_1$
• B. In $\left(c_2/c_1\right)$
• C. In $(c_1+c_2)$
• D. In $c_2$

Answer 1

Answer: (B)

In $\left(c_2/c_1\right)$

According to Nernst equations,

$E=E^o-\frac{0.0591}{n}logQ$

$E_{cell}=E_{cell}^o-\frac{0.059}{2}log\frac{\left[Z{n}^{2+}\right]}{\left[C{u}^{2+}\right]}$

Also,

$\Delta G=-nEF=-n{E}^{o}F-RTln\frac{\left[C{u}^{2+}\right]}{\left[Z{n}^{2+}\right]}$

$\therefore \Delta G$ is function of $ln\left(c_2/c_1\right)$