Question

The $pH$ of neutral solution at ${35}^{o}C$ is:

• A. 7
• B. < 7
• C. > 7
• D. zero

Answer 1

The correct option is B < 7

As the temperature increases $Kw$ increases. So $pH$ of neutral solution must be less than $7$ at ${35}^o$ $C$ as $pH=7$ at ${25}^o$ $C$

For example: $Kw$ is found out to be ${10}^{-12}$ instead of ${10}^{-14}$ at ${50}^o$ $C$

$pH=6$ at ${50}^o$ $C$

So, $pH<7$ at ${35}^o$ $C$