Nicotinic acid (Ka = 1.4 x 10−5) is represented by the formula HNic. For a solution which contains 0.10 mol of nicotinic acid per 2.0 litre of solution, the percent dissociation is:
1.66%
Let the initial concentration of Nicotinic acid be C molL-1
Let us write down the equation:
HNic ⇋ Nic− + H+
(1- α)C αC αC
Ka=[Cα][Cα]C(1−α)
1−α=1
Ka=Cα2
=1.4×10−5=0.05×α2
α2=1.4×10−50.05
=0.28×10−3
α=0.01673
Percentage dissociation=1.67 %