Question

Deduced from the following $E^{\circ }$ values of half cells, what combination of two half cells would result in a cell with the largest potential?
(i) $A^{3-}\to A^{2-}+e;E^{\circ }=1.5V$ (ii) $B^{2+}+e\to B^{+};E^{\circ }=2.1V$
(iii) $C^{2+}+e\to C^{+};E^{\circ }=+0.5V$ (iv) $D\to D^{2+}+2e;E^{\circ }=-1.5V$

• A. (i) and (iii)
• B. (i) and (ii)
• C. (ii) and (iv)
• D. (iii) and (iv)

Answer 1

The correct option is B

(i) and (ii)

$E^{\circ }of\left(B\right)>E^{\circ }$ of (A) so, (B) is at cathode and (A) is at anode