What is the $pH$ of a $0.005 \ M$ $Ba(OH)_2$ solution?

The concentration in $M$ of $OH^{-}$ in $0.001 \ M$ $H_2SO_4$ is

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.

The gastric juice in our stomach contains enough $HCl$ to make the hydrogen ion concentration about $0.01 \, mole/litre$. The $pH$ of gastric juice is

$50 \ mL$ of water is added to $50 \ mL$ of $0.01 \ M$ $Ba(OH)_2$ solution. Calculate the $pH$ of the resulting solution.

Water is added to $1.0 \ mL$ of $0.1 \ M$ $HCl$ solution to make the total volume $50 \ mL$. Calculate the $pH$ change of the solution.