For pure water:

Options

A. pH increase and pOH decreases with rise in temperature
B. pH decrease and pOH increases with rise in temperature
C. both pH and pOH increase with rise in temperature
D. both pH and pOH decrease with rise in temperature

Answer

D

Explanation

On heating pure water the value od ionic product of water increases i.e., `K_(w)=10^(-14)at 25^(@)C` and at `60^(@)C`
`K_(w)=10^(-12)`. Thus pH and pOH both becomes 6 and `60^(@)C (pH and pOH=7 at 25^(@)C)`.