Question

explain why inspite of the nearlysame electronegativity oxygen forms hydrogen bonding but chlorine does not.

Answer 1

The tendency for H bonding depends upon size and electronegativity value. Although the electreonegativity of O and Cl is nearly same yet chlorine does not form H bond due to its larger size (99pm) as compared to oxygen
(66pm). Hence owing to smaller size O forms H bonds but Cl cannot.