What is the $pH$ of a $10^{-4} \ M \ OH^{-}$ solution at $330 \ K$,if $K_w$ at $330 \ K$ is $10^{-13.6}$?

$pH$ of $HCl$ $(10^{-12} \ M)$ is

Which of the following solutions has the highest $pH$?

What is the $pH$ of $0.005 \ M \ NaOH$ solution?

Five solutions of $KOH$ are prepared as follows: $1st \to 0.1 \ mol$ in $1 \ L$,$2nd \to 0.2 \ mol$ in $2 \ L$,$3rd \to 0.3 \ mol$ in $3 \ L$,$4th \to 0.4 \ mol$ in $4 \ L$,$5th \to 0.5 \ mol$ in $5 \ L$. What is the $pH$ of the resulting mixture?

For a solution of $HCl$ assuming complete ionization,the $pH = 1$. Find the normality of a $H_2SO_4$ solution having the same $pH$.