Which gas is formed at the cathode in the chlor-alkali process?
Answer and explanation
Correct answer: Hydrogen
At the cathode, reduction takes place. In the aqueous brine solution, water molecules gain electrons and produce hydrogen gas and hydroxide ions: 2H₂O + 2e⁻ → H₂ + 2OH⁻. Chlorine forms at the anode, whereas nitrogen and sulphur dioxide are not products of this electrolysis. Hence hydrogen is the cathode gas and option A is correct.
Frequently asked questions
What is the correct answer to this question?
Hydrogen
Why is this the correct answer?
At the cathode, reduction takes place. In the aqueous brine solution, water molecules gain electrons and produce hydrogen gas and hydroxide ions: 2H₂O + 2e⁻ → H₂ + 2OH⁻. Chlorine forms at the anode, whereas nitrogen and sulphur dioxide are not products of this electrolysis. Hence hydrogen is the cathode gas and option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
