Question

Assertion : The `pH` of pure water is less than `7` at `60^(@)C`.
Reason : As the temperature increases, pure water becomes slightly acidic.
A. If both assertion and reason are true and the reason is the correct explantion of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If assertion is false but reason is true.

Answer 1

Correct Answer - C
The scale of `pH` (`0` to `14` at `25^(@)C`) change to (`0` to `lt14`) as the temperature rises because `K_(w)` of water increases with temperature. Note that `[H^(+)] =[OH^(-)]` and thus water remains neutral.