Question

The blue color of aqueous copper sulphate solution fades when it is electrolysed using platinum electrode.

• A. True
• B. False

Answer 1

The correct option is A

True

At Cathode:$C{u}^{2+}+2e^{-}->Cu$

Copper ions are discharged at the cathode in preference to the hydrogen ion and reduced to copper metal.

At anode:$O{H}^{-}->OH+e^{-}$

$4OH->2H_{2}O+O_2$

Hydrogen ions are discharged in preference to the sulphate ions.Hydroxyle ions being unstable are oxidized to water and oxygen ,this is why on prolonged electrolysis the blue colour changes to colourless.