Which gas is formed at the cathode in the chlor-alkali process and how is it identified?
Answer and explanation
Correct answer: Hydrogen and pop sound
In the chlor-alkali process, concentrated aqueous sodium chloride is electrolysed. Water is reduced at the cathode, producing hydrogen gas and hydroxide ions: 2H2O + 2e− → H2 + 2OH−. Hydrogen burns rapidly with a characteristic ‘pop’ when a burning splint is brought near it. Therefore option A is correct; chlorine is produced at the anode, not the cathode.
Frequently asked questions
What is the correct answer to this question?
Hydrogen and pop sound
Why is this the correct answer?
In the chlor-alkali process, concentrated aqueous sodium chloride is electrolysed. Water is reduced at the cathode, producing hydrogen gas and hydroxide ions: 2H2O + 2e− → H2 + 2OH−. Hydrogen burns rapidly with a characteristic ‘pop’ when a burning splint is brought near it. Therefore option A is correct; chlorine is produced at the anode, not the cathode.
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.
