The pH of aqueous sodium chloride solution is nearly 7. What is the correct reason?
Answer and explanation
Correct answer: It is a salt of a strong acid and a strong base
Sodium chloride is formed by the neutralisation of hydrochloric acid, a strong acid, with sodium hydroxide, a strong base: HCl + NaOH → NaCl + H₂O. In water, NaCl dissociates into Na⁺ and Cl⁻, but these ions do not significantly hydrolyse to produce excess H⁺ or OH⁻. Consequently, its aqueous solution is nearly neutral, with pH close to 7. Option D is false because the salt does ionise.
Frequently asked questions
What is the correct answer to this question?
It is a salt of a strong acid and a strong base
Why is this the correct answer?
Sodium chloride is formed by the neutralisation of hydrochloric acid, a strong acid, with sodium hydroxide, a strong base: HCl + NaOH → NaCl + H₂O. In water, NaCl dissociates into Na⁺ and Cl⁻, but these ions do not significantly hydrolyse to produce excess H⁺ or OH⁻. Consequently, its aqueous solution is nearly neutral, with pH close to 7. Option D is false because the salt does ionise.
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.
