pH of $10^{-8} \ M \ HCl$ solution is

Millimoles of calcium hydroxide required to produce $100 \ mL$ of the aqueous solution of $pH$ $12$ is $x \times 10^{-1}$. The value of $x$ is $..............$. (Nearest integer). Assume complete dissociation.

What is the $pH$ of a solution in which $25.0 \ mL$ of $0.1 \ M \ NaOH$ is added to $25 \ mL$ of $0.08 \ M \ HCl$ and the final solution is diluted to $500 \ mL$?

Calculate the $pH$ of the following solutions:
$(a)$ $2 \,g$ of $TlOH$ dissolved in water to give $2 \,L$ of solution.
$(b)$ $0.3 \,g$ of $Ca(OH)_2$ dissolved in water to give $500 \,mL$ of solution.
$(c)$ $0.3 \,g$ of $NaOH$ dissolved in water to give $200 \,mL$ of solution.
$(d)$ $1 \,mL$ of $13.6 \,M \,HCl$ is diluted with water to give $1 \,L$ of solution.

Given that the dissociation constant for $H_2O$ is $K_w = 1 \times 10^{-14} \ mol^2/L^2$. What is the $pH$ of a $0.001 \ M$ $KOH$ solution?

What is the $pH$ of a solution containing $4.62 \times 10^{-4} \ M \ H^{+}$ ions?