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

$600 \, mL$ of $0.01 \, M \, HCl$ is mixed with $400 \, mL$ of $0.01 \, M \, H_2SO_4$. The $pH$ of the mixture is $....... \times 10^{-2}$. (Nearest integer) [Given $\log 2 = 0.30, \quad \log 3 = 0.48, \quad \log 5 = 0.69, \quad \log 7 = 0.84, \quad \log 11 = 1.04$]

Calculate the $pH$ of the following solutions:
$(a)$ $0.002 \ M \ HNO_3$
$(b)$ $0.06 \ M \ H_2SO_4$

Find the number of equivalents of $HBr$ present in $100 \ mL$ of its solution whose $pH$ is $4$.

Which of the following solutions has the highest $pH = 14$?

What is the $pOH$ of a $1 \ mM$ solution of $Ca(OH)_2$?