Which of the following statements is (are) incorrect ?

Options

A. Electrolysis of sulphuric acid (dilute or concentrated) using inert electrodes give `H_(2)` at cathode and `O_(2)` at anode
B. Electrolysis of dilute NaOH solution gives `H_(2)` at cathode and `O_(2)` at anode
C. Oxidation of copper anode occurs in the electrolysis of aqueous copper sulphate solution using copper electrodes
D. Electrolysis of aqueous KF solution gives fluorine at the anode

Answer

A, D

Explanation

During electrolysis of `H_(2)SO_(4)`, the following two reactions are possible at anode:
For dilute: `H_(2)SO_(4), 2H_(2)O rarr O_(2) + 4H^(+) + 4e^(-)`
For concentrated: `H_(2)SO_(4), 2SO_(4)^(2-) rarr S_(2)O_(8)^(2-) + 2e^(-)`
`F^(-)` ions have much lower oxidation potential than `H_(2)O`
Hence, `F^(-)` ions are not oxidized in the aqueous solution to give `F_(2)`.