What are the products obtained at the cathode and anode during the electrolysis of the following when platinum electrodes are used in the electrolysis
a) Molten b) `Aq. CuSO_(4)` solution c) `Aq. K_(2)SO_(4)` solution

Explanation

a) During the electrolysis of molten KCl using platinum electrodes. Potassium is obtained at cathode and chlorine at anode.
`2CKl to 2K^(+)+2C^(-)`
`2Cl^(-) to Cl_(2)+2e^(-)` (anode)
`2K^(+)+2e^(-) to 2K` (cathode)
b) During the electrolysis of aq.` CuSO_(4)` solution using platinum electrodes, `O_(2)` gas liberated at anode and Cu deposited at cathode.
`2 CuSO_(4)to 2 Cu^(+2)+2SO_(4)^(-2)`
`2Cu^(+2)+4e^(-) 2 Cu` (cathode)
`2H_(2)O -4e^(-)to O_(2)+4H^(+)` (anode)
During the electrolysis of `aq. K_(2)SO_(4)` using pt-anode and pt-cathode hydrogen gas liberated at cathode and oxygen gas at anode.
`K_(2)SO_(4) to 2K^(+)+SO_(4) ^(-2)`
`4 H_(2) O overset(+4e ^(-))to2H_(2) +4OH^(-)`(cathode)
`2H_(2)Ooverset(-4e^(-))toO_(2)+ 4H^(+)` (anode)