Question

urgent.....
if the pka value of benzoic acid (C6H5) is considered to be 5.2 at 30°C .the pkb of its conjugate base C6H5COO_ is

Answer 1

pka and pkb of acid and its conjugate base is related by the equation:

$pka + pkb =pkw$

$pka + pkb =14$

Here pka is the dissocation constant for the acid and pkb is the dissociation constant for the base.

So if one knows pka then pkb can be calculated.

Here, pka is given as 5.2 so pkb calculated as

$pkb =14-pka$

$pkb =14-5.2$

pkb=8.8