Question

The sodium salt of a certain weak monobasic organic acid is hydrolysed to an extent of 3% in its 0.1 M solution at `25^@C`.Given that the ionic product of water is `10^(-14)` at this temperature , what is the dissociation constant of the acid ?
A. `~~1xx10^(-10)`
B. `~~1xx10^(-9)`
C. `3.33xx10^(-9)`
D. `3.33xx10^(-10)`

Answer 1

`h=0.3 C=0.1M`
`K_(h)=CH^(2)=9xx10^(-5)`
`K_(h)=(K_(w))/(K_(a))=9xx10^(-5)rArr K_(a)=(10^(-14))/(9xx10^(-5))=1.11xx10^(-10)~~1xx10^(-10)`