Explain a general step-wise approach to evaluate the $pH$ of the weak electrolyte.
Step-$1$ : The species present before dissociation are identified as Bronsted-Lowry acid/base.
Step-$2$: Balanced equations for all possible reaction. i.e. with a species acting both as acid as well as base are written.
Step-$3$: The reaction with the higher $\mathrm{K}_{a}$ is identified as the primary reaction whilst the other is a subsidiary reaction.
Step-$4$: Enlist in a tabular form the following values for each of the species in the primary reaction. $(i)$ Initial concentration $c$, $(ii)$ Change in concentration on proceeding to equilibrium in term of $(\alpha)$, degree of ionization. $(iii)$ Equilibrium concentration.
Step-$5$ : Substitute equilibrium concentrations into equilibrium constant equation for principal reaction and solve for $\alpha$.
Step-$6$: Calculate the concentration of species in principal reaction.
Step-$7$: Calculate $\mathrm{pH}=-\log \left[\mathrm{H}_{3} \mathrm{O}^{+}\right]$.
$0.01\, M \,HA(aq.)$ is $2\%$ ionized, $[OH^-]$ of solution is :-
The ionization constant of $0.1$ $M$ weak acid is $1.74 \times {10^{ - 5}}$ at $298$ $K$ temperature. Calculate $pH$ of its $0.1$ $M$ solution.
What is the $pH$ of solution of $7$ $gm$ $N{H_4}OH$ per $500$ $mL$ ? ( ${K_b}$ of $N{H_4}OH 1.8 \times {10^{ - 5}}$, Molecular moles of $N{H_4}OH$ is $35\,g\,mo{l^{ - 1}}$ )
Equal volumes of three acid solutions of $pH \,3, 4$ and $5$ are mixed in a vessel. .........$ \times 10^{-4} \,M$ will be the $H^+$ ion concentration in the mixture ?
For a weak acid, the incorrect statement is