Two platinum electrodes were immersed in a solution of $C u S O_{4}$ and electric current was passed through the solution. After some time, it was found that colour of $C u S O_{4}$ disappeared with evolution of gas at the electrode. The colorless solution contains:

Platinum sulphate

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Copper hydroxide

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Copper sulphate

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Sulphuric acid

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D Sulphuric acid
$C u S O_{4} (a q) E l e c t r o l s i s - ----- \to C u^{2 +} (a q) + S O_{4}^{2 -} (a q)$
At cathode: $C u^{2 +} (a q) + 2 e^{-} \to C u (r e d u c t i o n)$
The blue color of $C u S O_{4}$ disappears due to the deposition of Cu on Pt electrode.
At anode: $H_{2} O \to 2 H^{\oplus} + 2 e^{-} \frac{1}{2} O_{2} (g)$
Since oxidation potential of $H_{2} O$ > oxidation potential of $S O_{4}^{2 -}$ , so oxidation of $H_{2} O$ occurs and $O_{2} (g)$ is evolved at anode.
The colourless solution is due to the formation of $H_{2} S O_{4}$ as follows:
$2 H^{\oplus} (f r o m a n o d e) + S O_{4}^{2 -} \to H_{2} S O_{4}$

Suggest Corrections

Similar questions

Q. Two platinum electrodes were immersed in a solution of

C u S O_{4}

and electric current was passed through the solution. After some time, it was found that colour of

C u S O_{4}

disappeared with evolution of gas at the electrode. The colorless solution contains:

If electrodes were immersed in water, and a current was passed, is the change taking place in the solution a chemical change? Give reason.
[ 3 MARKS ]

100 mL

of a

0.05 M C u S O_{4} aqueous

solution was electrolysed using inert electrodes by passing current till the pH of the resulting solution was 2. The solution after electrolysis was neutralised and then treated with excess

K I

and the formed

I_{2}

was titrated with

0.04 M N a_{2} S_{2} O_{3}

. Calculate the volume of

N a_{2} S_{2} O_{3}

required in

mL

Q. Assertion :At the end of electrolysis using Pt electrodes, an aqueous solution of

C u S O_{4}

turns colorless. Reason:

C u S O_{4}

changes to

C u (O H)_{2}

during elctrolysis.

Q. Two aqueous solutions A and B containing solute

C u S O_{4}

and

N a B r

respectively were electrolysed using platinum electrodes. The pH of the resulting solutions will show a/an:

Join BYJU'S Learning Program

Two platinum electrodes were immersed in a solution of CuSO4 and electric current was passed through the solution. After some time, it was found that colour of CuSO4 disappeared with evolution of gas at the electrode. The colorless solution contains:

Two platinum electrodes were immersed in a solution of $C u S O_{4}$ and electric current was passed through the solution. After some time, it was found that colour of $C u S O_{4}$ disappeared with evolution of gas at the electrode. The colorless solution contains: