NTA Abhyas NEET2020ChemistryElectrochemistryPractice
A dilute aqueous solution of N a 2 S O 4 is electrolyzed using platinum electrodes. The products at the anode and cathode are :
Options
- AS 2 O 8 2 − , H 2
- BS 2 O 8 2 − ,     N a
- CO 2 ,     N a
- DO 2 , H 2
Correct answer
D. O 2 , H 2
Step-by-step solution
H 2 O is more readily reduced at cathode than N a + . It is also more readily oxidized at anode than S O 4 2 − . Hence, the electrode reactions are 2 H 2 O + 2 e − → H 2 ↑ + 2 O H − [ a t c a t h o d e ] H 2 O → 1 2 O 2 ↑ + 2 H + + 2 e − [ a t a n o d e ]