$0.1$ $mol$ of $H_2S(g)$ is kept in a $0.4$ litre vessel at $1000\,K$. For the reaction -
$2{H_2}S(g)\,\rightleftharpoons\,2{H_2}(g)\, + \,{S_2}(g)\,;\,{K_c} = {10^{ - 6}}\% $ dissociation of $H_2S$ is.......$\%$

$0.01$ moles of a weak acid $HA \left( K _{ a }=2.0 \times 10^{-6}\right)$ is dissolved in $1.0\, L$ of $0.1\, M\, HCl$ solution. The degree of dissociation of $HA$ is ............. $\times 10^{-5}$

(Round off to the Nearest Integer).

[Neglect volume change on adding $HA$. Assume degree of dissociation $<< 1]$

The $pH$ of the solution obtained on neutralisation of $40\, mL\, 0.1\, M\, NaOH$ with $40\, mL\, 0.1\, M\, CH_3COOH$ 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 ionisation constant of acetic acid is $1.8 \times 10^{-5}$. The concentration at which it will be dissociated to $2\%$, is

Write characteristic and uses of weak base equilibrium constant ${K_b}$.