Q. Equimolar solutions of $H F$ , $H COO H$ and $H CN$ at $298 K$ have the values of $K_{a}$ as $6.8 \times 1 0^{- 4}$ , $1.8 \times 1 0^{- 4}$ and $4.8 \times 1 0^{- 9}$ respectively. What will be the order of their acidic strength?

2436 231 Equilibrium Report Error

A

$H F > H CN > H COO H$

17%

B

$H F > H COO H > H CN$

67%

C

$H CN > H F > H COO H$

9%

D

$H COO H > H CN > H F$

7%

Solution:

Acidic strength $\propto K_{a}$