Question

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

• A. cannot be predicted
• B. $A+B^{+}\to A^{+}+B$
• C. $A^{+}+B\to A+B^{+}$
• D. $A^{+}+e^{-}\to A;B^{+}+e^{-}\to B$

Answer 1

Answer: (B)

$A+B^{+}\to A^{+}+B$

Cell is represented as

Anodic compartment $||$ Cathodic compartment

Thus, in

$A|A^{+}||B^{+}|B$

at Anode, oxidation of $A$ takes place.

at Cathode, reduction of $B^{+}$ takes place.

Cathode: $B^{+}+e^{-}⟶B$

Anode: $A⟶A^{+}+e^{-}$

Cell reaction= $B^{+}+A⟶A^{+}+B$

Thus Cell reaction is $B^{+}+A⟶A^{+}+B$