Assign $A, B, C, D$ from the given type of reaction.
$Zn(OH)_2 \downarrow + 2NaOH \longrightarrow Na_2ZnO_2 + 2H_2O$

If $20 \, mL$ of $0.25 \, N$ strong acid and $30 \, mL$ of $0.2 \, N$ strong base are mixed,then the resulting solution is

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)

For a concentrated solution of a weak electrolyte ($K_{eq} = $ equilibrium constant) $A_2B_3$ of concentration '$c$',the degree of dissociation '$\alpha$' is

The hydrolysis constants of salts $M_1X$ and $M_2X$ formed from a strong acid and weak bases are $10^{-7}$ and $10^{-4}$ respectively. For base $M_3OH$,$K_b = 10^{-4}$. The decreasing order of basic strength is:

One litre of water contains $10^{-7} \ mole$ of hydrogen ions. The degree of ionization in water will be: