Assertion : The pH of pure water is less than 7 at `60^(@)C.`
Reason : As the temperature increases, pure water becomes slightly acidic.

Options

A. If both (A) and (R) are correct and (R) is the correct explanation of (A).
B. If both (A) and (R) are correct, but(R) is not the correct explanation of (A)
C. If(A) is correct, but (R) is incorrect
D. If both (A) and (R) are incorrect

Answer

C

Explanation

The scale of pH (0 to 14 at `25^(@)C`) changes to (0 to less than 14) as the temperature rises because `K_(w)` of water increases with temperatu `[H ^(+) ] =[OH ^(-)]` and thus water remains neutral.