Question

The platinum electrodes were immersed in a solution of cupric sulphate and electric current passed through the solution. After some time it was found that colour of copper sulphate disappeared with evolution of gas at the electrode. The colourless solution contains.

• A. Platinum sulphate
• B. Copper hydroxide
• C. Copper sulphate
• D. Sulphuric acid

Answer 1

Answer: (D)

Sulphuric acid

Answer 2

During electrolysis of $CuSO_{4}$.$Cu^{2 +}$ gets discharged at cathode and $OH^{-}$at anode. Thus solution becomes acidic due to excess of $H^{+}$ and $SO_{4}^{2 -}$ or $H_{2}SO_{4}$.