Give reasons:

(i) PCl₅ is more covalent than PCl₃.

(ii) O-O bond has lower bond dissociation enthalpy than S-S bond.

(iii) F₂ is a stronger oxidizing agent than Cl₂.

(i) PCl₅ is more covalent than PCl₃ because greater the oxidation state of phosphorus atom, more will be the polarizing power which increases the covalent character. P is in +5 oxidation state in PCl₅ and in +3 oxidation state in PCl_3. Thus, PCl₅ is more covalent.

(ii) O-O bond has lower bond dissociation enthalpy than S-S bond because O has smaller size than S due to which the O-O bond length is short which results in repulsion of lone pairs on O making it unstable and the bond can be cleaved easily. Whereas due to big size of S, no such repulsion is present and the S-S bond is stronger than that between O-O.

(iii) F₂ is a stronger oxidizing agent than Cl₂ because fluorine is more electronegative than chlorine therefore it can attract a shared pair of electron more easily and strongly as compared to chlorine. Moreover, its small size and low bond dissociation enthalpy also makes it a stronger oxidizing agent.