Arrange benzene, n -hexane and ethyne in decreasing order of their acidic behaviour.

Step-by-step solution

The decreasing order of acidic behaviour is ethyne > benzene >n -hexane Because carbon in ethyne, benzene and n -hexane are s p, s p² and s p³ hybridised respectively. The carbocation formed after the removal of ' H ' is more stable in s p hybridised carbon atom because of high electronegativity due to more s -character.