Four solutions have pH values 5, 7, 9 and 11. Which acidic solution among them is least harmful to teeth?
Answer and explanation
Correct answer: Solution with pH 5
On the pH scale, only pH 5 is acidic; pH 7 is neutral, while pH 9 and 11 are basic. Therefore, if the question asks specifically for the acidic solution, option A is the only valid choice. Tooth enamel begins to face increased risk in sufficiently acidic conditions, commonly discussed near pH 5.5, so a lower pH is generally more harmful. The wording should not be read as saying pH 5 is harmless; it is simply the only acidic option listed.
Frequently asked questions
What is the correct answer to this question?
Solution with pH 5
Why is this the correct answer?
On the pH scale, only pH 5 is acidic; pH 7 is neutral, while pH 9 and 11 are basic. Therefore, if the question asks specifically for the acidic solution, option A is the only valid choice. Tooth enamel begins to face increased risk in sufficiently acidic conditions, commonly discussed near pH 5.5, so a lower pH is generally more harmful. The wording should not be read as saying pH 5 is harmless; it is simply the only acidic option listed.
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.
