The correct option is A 10−4
Given, Ka=10−5, [NaX]=0.1 M
According to question, NaX is a salt of weak acid and strong base.
Therefore X− only undergoes hydrolysis.
at equilibrium we have,
'Kh' is hydrolysis constant and 'C' is concentration
⇒degree of hydrolysis (h)=10−4
percentage degree of hydrolysis=10−4×100=0.01