Question

The pKa of acetic acid is 4.76. The pKa of trichloro acetic acid is 0.7. Calculate the equilibrium dissociation constant of each acid.

Answer 1

Answer:

Ka for acetic acid = $1.8\times 10^{-5}$

Ka for trichloro acetic acid is 0.2

Explanation:

Given that:-

pKa of acetic acid is 4.76

The expression for the relation between pKa and Ka is shown below as:-

pKa = - log Ka

So,

$Ka = 10^{-pKa}$

Applying the values as:-

$Ka = 10^{-4.76}=1.8\times 10^{-5}$

For, trichloro acetic acid, pKa= 0.7

SO,

$Ka = 10^{-0.7}=0.2$