Question

For the cell reaction : $C{u}^{2+}\left(aq\right)\left(C_1\right)+Zn\left(s\right)\to Z{n}^{2+}\left(aq\right)\left(C_2\right)+Cu\left(s\right)$ the change in free energy $\Delta G$ at a given temperature is a function of

• A. $ln{C}_1$
• B. $ln\left(\frac{C_2}{C_1}\right)$
• C. $ln(C_2+C_2)$
• D. $ln\left(C_2\right)$

Answer 1

The correct option is B $ln\left(\frac{C_2}{C_1}\right)$

We know $\Delta G=nFE$

Again according to Nernst equation,

$E=\frac{0.059}{n}log$$\frac{\left[Z{n}^{2+}\right]}{\left[C{u}^{2+}\right]}$ $at$ ${25}^{0}C$

So $\Delta G$ (free energy change) in an electrochemical cell at a given temperature is a function of

$ln$$\frac{\left[Z{n}^{2+}\right]}{\left[C{u}^{2+}\right]}=ln\frac{C_2}{C_1}$