Question

A hypothetical electrochemical cell is shown below
$A\left|A^{+}(xM)\right|\left|B^{+}(yM)\right|B$
The EMF measured is $+0.20V$. The cell reaction is

• A. $A+B^{+}\to A^{+}+B$
• B. $A^{+}+B\to A+B^{+}$
• C. $A^{+}+e^{-}\to A,B^{+}+e^{-}\to B$
• D. the cell reaction cannot be predicted

Answer 1

Answer: (A)

Electrochemical cell,
$A\left|A^{+}(xM)\Vert B^{+}(yM)\right|B$
The EMF of cell is $+0.20V$.
So, cell reaction is possible.
The half-cell reactions are given as follows
(i) At negative pole
$A⟶A^{+}+e^{-}$(oxidation)
(ii) At positive pole
$B^{+}+e^{-}⟶B$(reduction)
Hence, cell reaction is
$A+B^{+}⟶A^{+}+B,E_{\text{cell }}^{\circ }=+0.20V$