If $10^{-6} \ M \ HCl$ is diluted $100$ times,its $pH$ will be:

How many liters of water must be added to $1 \ L$ of an aqueous $HCl$ solution with $pH = 1$ to change its $pH$ to $2$?

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

By adding $20 \ mL$ of $0.1 \ N \ HCl$ to $20 \ mL$ of $0.001 \ N \ KOH$,the $pH$ of the resulting solution will be:

$75 \ mL$ of $0.2 \ M \ HCl$ is mixed with $25 \ mL$ of $1 \ M \ HCl$. To this solution, $300 \ mL$ of distilled water is added. What is the $pH$ of the resultant solution?

$4 \ g$ of $NaOH$ is added in water to form $500 \ mL$ solution at $298 \ K$. What is the $pH$ of the solution? (Molar mass of $NaOH = 40 \ g \ mol^{-1}$)