A solution has pH 7 but contains a dissolved salt. Which salt is most likely?
Answer and explanation
Correct answer: Sodium chloride
The governing concept is the nature of salts formed from strong or weak acids and bases. Sodium chloride is produced from hydrochloric acid, a strong acid, and sodium hydroxide, a strong base. Its ions do not significantly hydrolyse water, so its aqueous solution is approximately neutral with pH 7. Sodium carbonate is basic, ammonium chloride is acidic, and sodium hydroxide is a base rather than a salt. Therefore, option A is correct.
Frequently asked questions
What is the correct answer to this question?
Sodium chloride
Why is this the correct answer?
The governing concept is the nature of salts formed from strong or weak acids and bases. Sodium chloride is produced from hydrochloric acid, a strong acid, and sodium hydroxide, a strong base. Its ions do not significantly hydrolyse water, so its aqueous solution is approximately neutral with pH 7. Sodium carbonate is basic, ammonium chloride is acidic, and sodium hydroxide is a base rather than a salt. Therefore, 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.
