The Ph OF NEUTRAL WATER AT `25^(@)C` is `7.0.` As the temperature increases, ionisation of water increases, however the concentration of `H^(+)` ions nad `OH^(-)` ions equal. What will be the ph of puire water at `60^(@)C`?

Options

A. Equal to 7.0
B. Greater than 7.0
C. Less than 7.0
D. Equal to zero

Answer

C

Explanation

At `25^(@)C, [H^(+)]=[OH^(-)]=10^(-7) and K_(w) = [H^(+)][OH^(-)]=10^(-14)`. On heating, `K_(w)` increases , i.e, `[H^(+)][OH^(-)] gt 10^(-14)`. As `[H^(+)]=[OH^(-)],[H^(+)]^(2) gt 10^(-14) ` or `[H^(+)] gt 10^(-7) M or pH lt 7`.