# The dissociation constant for aniline, acetic acid, and water at are $3.83 \times {10^{ - 10}},1.75 \times 1{O^{ - 5}},$and $1.008 \times {10^{ - 14}}$ respectively. What is the degree of hydrolysis of aniline acetate in a deci normal solution and pH?

\[

A.\;\;\;\;\;h = 54.95\% {\text{ }};{\text{ }}pH = 6.4683 \\

B.\;\;\;\;\;h = 45.95\% ;{\text{ }}pH = 4.6683 \\

C.\;\;\;\;\;h = 54.955\% ;{\text{ }}pH = 4.6683 \\

D.\;\;\;\;\;none{\text{ }}of{\text{ }}these \\

\]

Answer

Verified

335.1k+ views

**Hint:**

Degree of hydrolysis is the fraction (or percentage) of total salt which is hydrolysed at equilibrium whereas dissociation constant (ka) is the ratio of dissociated ions (products) to original acid (reactants).

**Formula used:**

\[

i)\,\,\,{K_h} = \dfrac{{{k_w}}}{{{k_a} \times {k_b}}}\; \\

ii)\;\;h = \dfrac{{\sqrt {{k_h}} }}{{1 + \sqrt {{k_h}} }} \\

iii)\,\,pH = \dfrac{1}{2}(p{K_{w\;\;}} - p{K_{a\;\;}} - p{K_{b\;\;}}) \\

\]

**Complete step by step answer:**

The expression for hydrolysis constant ${K_h} = \dfrac{{1 \times {{10}^{ - 14}}}}{{1.75 \times {{10}^{ - 5\;\;\;}} \times 3.83 \times {{10}^{ - 10}}}}$ (from formula i)

= 1.49

The expression for the degree of hydrolysis is ,\[\;h = \dfrac{{\sqrt {{k_h}} }}{{1 + \sqrt {{k_h}} }}\]

Therefore, \[h = \dfrac{{\sqrt 1 .49}}{{1 + \sqrt 1 .49}}\]

= 0.5495

Hence, percentage of hydrolysis \[ = {\text{ }}100X{\text{ }}0.5459\]

\[ = {\text{ }}54.95\% \]

Further, \[pH = \dfrac{1}{2}(p{K_{w\;\;}} - p{K_{a\;\;}} - p{K_{b\;\;}})\]

\[ = \dfrac{1}{2}\log \left[ {1.008 \times {{10}^{ - 14\;}}} \right] - \log \left[ {1.75 \times {{10}^{ - 5\;}}} \right] - \log \left[ {3.83 \times {{10}^{ - 10\;}}} \right]\]

\[ = 4.6683\]

**Hence, option c is correct.**

**Note:**

If ${K_{h\;\;}} = {h^2}\;$ is assumed (assuming \[1 - h \approx 1\]), the value of h comes greater than 1 which is not possible and thus 1-h should not be neglected. (from${K_{h\;\;\;\; = \;\;\;}}\dfrac{{{h^2}}}{{1 - h}}$ , which is another method )

Last updated date: 25th Sep 2023

â€¢

Total views: 335.1k

â€¢

Views today: 5.35k

Recently Updated Pages

What do you mean by public facilities

Difference between hardware and software

Disadvantages of Advertising

10 Advantages and Disadvantages of Plastic

What do you mean by Endemic Species

What is the Botanical Name of Dog , Cat , Turmeric , Mushroom , Palm

Trending doubts

How do you solve x2 11x + 28 0 using the quadratic class 10 maths CBSE

What is the IUPAC name of CH3CH CH COOH A 2Butenoic class 11 chemistry CBSE

Drive an expression for the electric field due to an class 12 physics CBSE

Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE

Fill the blanks with the suitable prepositions 1 The class 9 english CBSE

Difference Between Plant Cell and Animal Cell

The dimensions of potential gradient are A MLT 3A 1 class 11 physics CBSE

Define electric potential and write down its dimen class 9 physics CBSE

Why is the electric field perpendicular to the equipotential class 12 physics CBSE