Question

Discuss the following property and its variation with reference to the elements of group 17:

Oxidising nature

Answer 1

1. Halogens (Group 17 elements) have 7 electrons in their outer shell and easily gain 1 electron to form halide ions (X⁻), showing strong oxidising nature.
2. This means they accept electrons and get reduced in reactions.
3. Fluorine has the strongest oxidising power due to its highest electronegativity and standard reduction potential.
4. The oxidising power decreases down the group from fluorine to iodine.
5. Fluorine can oxidise chlorine, bromine, and iodine ions, while chlorine can oxidise bromine and iodine ions, and bromine can oxidise only iodine ions.
6. The decrease in oxidising power is due to lower reduction potential and increased atomic size down the group.

Thus, oxidising nature decreases from F₂ > Cl₂ > Br₂ > I₂ in group 17 elements.