Question

Other things being equal, the EMF of a Daniell cell may be increased by

• A. Keeping low temperature
• B. Using large copper electrodes
• C. Using large zinc electrodes
• D. Decreasing concentration of $C{u}^{2+}$ ions

Answer 1

The correct option is A Keeping low temperature

For Daniell cell,

$Zn+C{u}^{2+}\to Z{n}^{2+}+Cu$

$E_{cell}=E_{cell}^{\circ }-\frac{RT}{nF}ln\frac{\left[Z{n}^{2+}\right]}{\left[C{u}^{2+}\right]}$

Thus, the decrease in temperature and increase in $\left[C{u}^{2+}\right]$ will increase the EMF.