Question

Choose the correct option(s) for electroplating of gold $\left(Au\right)$ onto a silver $\left(Ag\right)$ medal.

• A. $Au\left(s\right)$ electrode is taken at cathode
• B. $Au\left(s\right)$ electrode is taken at anode
• C. Both $Au\left(s\right)$ and $Ag\left(s\right)$ electrode is taken at cathode
• D. $Ag\left(s\right)$ electrode is taken at anode

Answer 1

The correct option is B $Au\left(s\right)$ electrode is taken at anode

Electroplating:An application of electrolytic process, for protecting against corrosion and to improve appearance.
Electroplating of gold $\left(Au\right)$ onto a silver $\left(Ag\right)$ medal:
$Au\left(s\right)$ electrode is taken at anode $Ag\left(s\right)$ electrode is taken at cathode
Anode reaction :
$Au\left(s\right)\rightleftharpoons A{u}^{3+}\left(aq\right)+3e^{-}$
The $A{u}^{3+}\left(aq\right)$ ions react with the $C{N}^{-}$ ions in solution to form $\left[Au\right(CN{)}_4{]}^{-}$ complex ion.

Cathode reaction:
$\left[Au\right(CN{)}_4{]}^{-}\left(aq\right)+3e^{-}\rightleftharpoons Au\left(s\right)+4C{N}^{-}\left(aq\right)$