Arrange the following solutions in the decreasing order of $pOH$:
$A$. $0.01 \ M \ HCl$
$B$. $0.01 \ M \ NaOH$
$C$. $0.01 \ M \ CH_3COONa$
$D$. $0.01 \ M \ NaCl$

$K_a$ for $CH_3COOH$ is $1.9 \times 10^{-5}$. Calculate the $pH$ at the equivalence point in the titration of $0.1 \ M$ $CH_3COOH$ with $0.1 \ M$ $NaOH$.

The concentration of $[H^{+}]$ and concentration of $[OH^{-}]$ of a $0.1 \ M$ aqueous solution of $2\%$ ionised weak acid is [Ionic product of water $= 1 \times 10^{-14}$]

At $27^{\circ} C$,the degree of dissociation of $HA$ (weak acid) in $0.5 \ M$ of its solution is $1 \%$. The concentrations of $H_3O^{+}$,$A^{-}$,and $HA$ at equilibrium (in $mol \ L^{-1}$) are respectively

At $25 \, ^\circ C$,the dissociation constant of pure water is equal to .......

The conductivity of a weak acid $HA$ of concentration $0.001 \, mol \, L^{-1}$ is $2.0 \times 10^{-5} \, S \, cm^{-1} .$ If $\Lambda_{m}^{\circ} (HA)=190 \, S \, cm^{2} \, mol^{-1}$,the ionization constant $(K_{a})$ of $HA$ is equal to $....\, \times 10^{-6} .$ (Round off to the Nearest Integer)