Question

What will be the products of electrolysis of an aqueous solution of $AgNO_{3}$with silver electrodes?

• A. Ag from Ag anode dissolves while $Ag^{+}$from solution gets deposited on cathode.
• B. Ag is liberated at cathode and $O_{2}$is liberated at anode.
• C. Ag at cathode and nitric acid at anode is liberated.
• D. No reaction takes place.

Answer 1

Answer: (A)

Ag from Ag anode dissolves while $Ag^{+}$from solution gets deposited on cathode.

Answer 2

: $AgNO_{3} \rightarrow Ag^{+} + NO_{3}^{-}$ (aqueous solution)

At cathode: $Ag_{(aq)}^{+} + e^{-} \rightarrow Ag:E^{o} = + 0.80V$

$2H_{2}O_{(l)} + 2e^{-} \rightarrow H_{2} + 2OH^{-};E^{o} = - 0.83V$

Since reduction potential of $Ag^{+}$ is higher than $H_{2}O,$ $Ag^{+}$ anode:

$Ag \rightarrow Ag_{(aq)}^{+} + e^{-};E^{o} = - 0.80V$

$2H_{2}O \rightarrow O_{2} + 4H^{+} + 4e^{-};E^{o} = - 1.23V$

Since oxidation potential of Ag is higher than $H_{2}O$, Ag of silver anode is oxidised. The oxidation potential of

$NO_{3}^{-}$ is lower than $H_{2}O$.