The pH of ammonium chloride solution is found to be less than 7. What is the correct reason?
Answer and explanation
Correct answer: It is a salt of a strong acid and a weak base
The governing concept is hydrolysis of salts. Ammonium chloride is formed from hydrochloric acid, a strong acid, and ammonium hydroxide, a weak base. In water, the ammonium ion hydrolyses and produces H3O+, making the solution acidic and giving pH below 7. Hence option A is correct. A strong-acid/strong-base salt is generally neutral, while the other choices do not describe NH4Cl.
Frequently asked questions
What is the correct answer to this question?
It is a salt of a strong acid and a weak base
Why is this the correct answer?
The governing concept is hydrolysis of salts. Ammonium chloride is formed from hydrochloric acid, a strong acid, and ammonium hydroxide, a weak base. In water, the ammonium ion hydrolyses and produces H3O+, making the solution acidic and giving pH below 7. Hence option A is correct. A strong-acid/strong-base salt is generally neutral, while the other choices do not describe NH4Cl.
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.
