Two platinum electrodes were immersed in a solution of `CuSO_(4)` and electric current was passed through the solution. After some time, it was found that the colour of `CuSO_(4)` disappeared with the evolution of `O_(2)(g)` at the electrode. the colourless solution contains

Options

A. platinum sulphate
B. copper hydroxide
C. copper sulphate
D. sulphuric acid

Answer

d

Explanation

Aqueous solution of `CuSO_(4)overset(El ectrolysis)rarr Cu^(2+)+SO_(4)^(2-)`
At cathode `: Cu^(2+)+2e^(-)rarr Cu (` Reduction `)`
At anode `: H_(2)O rarr 2H^(o+)+2e^(-)+(1)/(2)O_(2)(` Oxidation `)`
The blue colour of aqueous `CuSO_(4)` is discharged to the reductionof `Cu^(2+)` to `Cu` and the solution is acidic due to the formation of `H^(o+)` ions. So `pH` of solution, `X`, less than 7.