Question

The value of $K_w$ at the physiological temperature $\left({37}^{o}C\right)$ is $2.56\times {10}^{-14}$. What is the $pH$ at the neutral point of water at this temperature, where there are equal number of $H^{+}$ and ${OH}^{-}$ ions?

[Note: answer in nearest integer]

Answer 1

As we know,

$p{K}_w=log(2.56\times {10}^{-14})=14-\log 2.56=13.59\approx 13.6$

$pH=\frac{p{K}_w}{2}=6.795$

So, the nearest integer is 7.