Manipal Entrance Test 2019 Chemistry Paper

In hydrolysis of a salt of weak acid and strong base.
A−+H2O⇌HA+OH−
the hydrolysis constant Kh
Kh=

[HA][OH−]

[A−]

(According to law of mass action)
(∵ conc. of water remains constant)
For the ionisation of weak acid HA,
we has HA⇌H++A−
Ka=

[H+][A−]

[HA]

Also we know that

Kw

Ka

=

[H+][OH−][HA]

[H+][A−]

Kw

Ka

=

[OH−][HA]

[A−]

=Kh