NEETChemistryHydrogen
What reactions occur at the anode and cathode during the electrolysis of brine solution?
Options
- AAt anode: 2H 2 O(l) → 2H 2(g ) + O 2(g) ; At cathode: 2Cl– (aq ) → Cl 2(g ) + 2e–
- BAt anode: 2Cl–(aq) → Cl 2 (g) + 2e–; At cathode: 2H 2 O(l) → 2H 2 (g) + 2OH–(aq)
- CAt anode: 2H 2 O(l) → 2H 2 (g) + 2OH–(aq); At cathode: 2Cl–(aq) → Cl 2 (g) + 2e–
- DAt anode: 2Na+(aq) + 2OH–(aq) → 2NaOH(l); At cathode: 2H 2 O(l) → 2H 2 (g) + O 2 (g)
Correct answer
B. At anode: 2Cl–(aq) → Cl 2 (g) + 2e–; At cathode: 2H 2 O(l) → 2H 2 (g) + 2OH–(aq)
Step-by-step solution
At the anode, 2Cl– ions lose electrons and form chlorine gas (Cl 2 ), while at the cathode, 2H 2 O molecules gain electrons and form hydrogen gas (H 2 ) and hydroxide ions (OH–).