Question

Degree of dissociation of 0.1 N $C{H}_{3}COOH$ is:
[Dissociation constant is 1 $\times {10}^{-5}$]

• A. ${10}^{-5}$
• B. ${10}^{-4}$
• C. ${10}^{-3}$
• D. ${10}^{-2}$

Answer 1

The correct option is D ${10}^{-2}$

$C{H}_{3}COOH\rightleftharpoons C{H}_{3}CO{O}^{-}+H^{+}$ [where, $x=0.1$]

$C-C\alpha$ $C\alpha$ $C\alpha$

then,

$K_a=\frac{C\alpha \times C\alpha }{C(1-\alpha )}=\frac{C{\alpha }^2}{1-\alpha }$

${10}^{-5}=\frac{0.1{\alpha }^2}{1-\alpha }$ [$\because \alpha <<1$]

$\Rightarrow \alpha ={10}^{-2}$

Hence, the correct option is D.