A solution is diluted slowly, but its pH does not move far from 7 because it was already neutral. Which solution could it be?
Answer and explanation
Correct answer: Aqueous sodium chloride solution
The governing concept is the nature of salts formed from strong acids and strong bases. Sodium chloride is produced from hydrochloric acid and sodium hydroxide, so its aqueous solution is generally neutral, with pH close to 7. Dilution lowers the concentrations of both sodium and chloride ions but does not create a significant excess of hydrogen or hydroxide ions. Hydrochloric acid and sodium hydroxide would remain acidic or basic, while sodium carbonate is basic.
Frequently asked questions
What is the correct answer to this question?
Aqueous sodium chloride solution
Why is this the correct answer?
The governing concept is the nature of salts formed from strong acids and strong bases. Sodium chloride is produced from hydrochloric acid and sodium hydroxide, so its aqueous solution is generally neutral, with pH close to 7. Dilution lowers the concentrations of both sodium and chloride ions but does not create a significant excess of hydrogen or hydroxide ions. Hydrochloric acid and sodium hydroxide would remain acidic or basic, while sodium carbonate is basic.
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.
