Question

Calculate the ratio of degree of dissociation of acetic acid and hydrogen cyanide acid $\left(HCN\right)$ in $1M$ their respective solution of acids.

[Given $K_{a\left({CH}_{3}COOH\right)}=1.8\times {10}^{-5};K_{a\left(HCN\right)}=6.2\times {10}^{-10}$)

• A. 10
• B. 170
• C. 120
• D. 150

Answer 1

The correct option is B 170

We know,

$K_a=C{\alpha }^2$

$\frac{{\alpha }_1}{{\alpha }_2}=\sqrt{\frac{{Ka}_1}{{Ka}_2}}=\sqrt{\frac{1.8\times {10}^{-5}}{6.2\times {10}^{-10}}}=170.4$