A $0.1\,N $ solution of an acid at room temperature has a degree of ionisation $ 0.1$ . The concentration of $O{H^ - }$ would be

$25$ $mL$ $0.1$ $M$ $HCl$ solution is diluted till $500$ $mL$. Calculate $pH$ of dilute solution.

A weak acid is $ 0.1\% $ ionised in $0.1\, M $ solution. Its $pH$  is

If $pK_a =\, -\,log K_a=4$ for a weak acid $HX$ and $K_a= C\alpha ^2$ then Van't Haff factor when $C = 0.01\,M$ is

A certain amount of $H_2CO_3$ & $HCl$ are dissolved to form $1$ litre solution. At equilibrium it is found that concentration of $H_2CO_3$ & $CO_3^{-\,-}$ are $0.1\,M$ & $0.01\,M$ respectively. Calculate the $pH$ of solution. Given that for $H_2CO_3$ $K_{a_1} =10^{-5}$ & $K_{a_2} =10^{-8}$

The percentage of pyridine $(C_5H_5N)$ that forms pyridinium ion $(C_5H_5N^+H)$ in a $0.10\, M$ aqueous pyridine solution ($K_b$ for $C_5H_5N = 1.7 \times 10^{-9}$) is