Describe the following about halogen family (group 17 elements):
(i)    Relative oxidising power.
(ii)    Relative acidic strength of their hydrides.
(iii)    Oxyacids and their relative oxidising ability.

i) Halogen family have ready acceptance of an electron is the reason for the strong oxidising nature of halogens. F₂ is the strongest oxidising halogen and it oxidises other halide ions in solution or even in the solid phase.

ii) Halogens combine with hydrogen to form volatile halides of the formula HX.The bond between hydrogen and halogen is covalent in all the cases.

Acidic Strength. All the hydrogen halides act as acids in their aqueous solutions. The acidic strength varies in the order

HF < HCl < HBr < HI

Reason. All the halogen acids ionise to give H⁺ ion and halide ion, x-.

HX  à H⁺  +  X-  ; (where X ^- = F^- , Cl^- , Br^- , I^-)

The above order of acidic character can be explained in terms of strength of H-X bonds, which is in the order H-I< H-Br < H-Cl < H-F. Since H-1 bond is weakest, therefore, HI is the strongest acid. On the other hand H-F bond is strongest, hence it is the weakest acid among all the halogen acids.

iii)