During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment,
- the litmus turns blue but no gas is evolved
- the litmus turns blue and oxygen is evolved
- the litmus turns blue and hydrogen is evolved
-
the litmus turns red and oxygen is evolved
- the litmus turns red and then becomes colourless
The correct answer is: D
Explanation
Cu\(^+\) is discharged preferentially at the cathode
OH\(^-\) is discharged preferentially at the anode
The presence of SO\(_4\)\(^2-\) and H\(^+\) makes the medium acidic
Which makes the litmus turns red and oxygen is evolved