Question

$ Zn_{(s)} + Cl_2 (1 \, atm) \rightarrow Zn^{2+} + 2 Cl^- ; E^{\circ} = 2.0 \,V$ To increase the e.m.f. of the above cell

• A. $[Zn^{2+}]$ should be increased
• B. $[Zn^{2+}]$ should be decreased
• C. $[Cl^{-}]$ should be increased
• D. partial pressure of $Cl_2$ should be decreased.

Answer 1

Answer: (B)

$ E_{cell} = E^{\circ}_{cell} - \frac{0.0591}{2} \log [Zn^{2+}][Cl^-]^2 $
Hence, decrease in $[Zn^{2+}]$ will increase $ E_{cell} $