Question

The dissociation constant of formic acid and acetic acid are 2.14×10^-4 and 1.81×10^-5 respectively. What is the relative strength of the acids

Answer 1

Answer: The formic acid is 3.5 times stronger than acetic acid.

Step-by-step explanation:

The strength of an acid depends on its acid dissociation constant.

For a hypothetical monoprotic acid HA, the dissociation equilibrium is:

`HA\rightleftharpoons H^++A^-`

`K_a=([H^+][A^-])/([HA])`

More is the value of
`K_a` , greater is the dissociation and stronger is the acid.

`\frac{Strength_{\text {formic acid}}}{Strength_{\text {acetic acid}}}=\sqrt{(2.14* 10^(-4))/(1.81* 10^(-5))}=3.5`

Thus formic acid is 3.5 times stronger than acetic acid.