Question

Out of hf, hcl, hbr and hi, which has the weakest acid

Answer 1

Answer:

HF is the weakest acid because of it's strong H-F bond. Fluorine being small in size overlaps better with 1s orbital of hydrogen  leading to a strong bond.Hence can not give proton easily.Here bond strength overweighs the electronegativity of F .

As we go down the group, size of the halogens increases.This results in poor overlap of it's orbital with 1s  orbital of hydrogen making the H-X bond weaker. H-I bond is the weakest of all , so it is the strongest acid