What are Diprotic and Triprotic acid ? differentiation eat .
Polyprotic acid : The acids which have more than one ionizable proton per molecule of the acid. Such acids are known as polybasic or polyprotic acids.
Diprotic acid : The acid which have two ionizable proton per molecule of the acid. Such acids are known as Dibasic or Diprotic acid.
e.g., $\mathrm{H}_{2} \mathrm{X}+{ }_{\text {(aq) }}+2 \mathrm{H}^{+}+\mathrm{X}^{2-} \quad \mathrm{K}_{a}$
The ionization of the reaction is in two steps is as under,
$(i)$ $\mathrm{H}_{2} \mathrm{X}+\mathrm{H}_{2} \mathrm{O}+\mathrm{H}_{3} \mathrm{O}^{+}+\mathrm{HX}^{-} \quad \mathrm{K}_{a}$ (i)
$(ii)$ $\mathrm{HX}^{-}+\mathrm{H}_{2} \mathrm{O}+\mathrm{H}_{3} \mathrm{O}^{+}+\mathrm{X}^{2-} \quad \mathrm{K}_{a}$ (ii)
In it, $\mathrm{K}_{a}$ (i) $>\mathrm{K}_{a}$ (ii) and $\mathrm{K}_{a}$ (i) $\times \mathrm{K}_{a}$ (ii) $=\mathrm{K}_{a}$
Examples of diprotic acid : Oxalic acid $\left(\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}\right)$, Sulphuric acid $\left(\mathrm{H}_{2} \mathrm{SO}_{4}\right)$, Carbonic acid
$\left(\mathrm{H}_{2} \mathrm{CO}_{3}\right)$, Sulphurous acid $\left(\mathrm{H}_{2} \mathrm{SO}_{3}\right)$, Ascorbic acid etc.
Examples of triprotic acid : Phosphoric acid $\left(\mathrm{H}_{3} \mathrm{PO}_{4}\right)$, Cytaric acid.... etc.
In polyprotic acid solution constant mixture of acid like $\mathrm{H}_{2} \mathrm{~A}, \mathrm{HA}^{-}$and $\mathrm{A}^{2-}$.
What is the dissociation constant for $NH_4OH$ if at a given temperature its $0.1\,N$ solution has $pH = 11.27$ and the ionic product of water is $7.1 \times 10^{-15}$ (antilog $0.73 = 5.37$ )
A weak acid is $ 0.1\% $ ionised in $0.1\, M $ solution. Its $pH$ is
The hydrogen ion concentration in weak acid of dissociation constant ${K_a}$ and concentration $c$ is nearly equal to
Calculate $pH$ of $0.02$ $mL$ $ClC{H_2}COOH$. Its ${K_a} = 1.36 \times {10^{ - 3}}$ calculate its $pK_{b}$,
Derive the equation of relation between weak base ionization constant ${K_b}$ and its conjugate acid ionization constant ${K_a}$