In ClO2,Cl is sp2 hybridised and the bond angle is 118∘ . In ClO2,O is sp3 hybridised. However, due to repulsions between two big sized Cl atoms, the bond angle increases from 109∘−281 to 111∘ . In ClO2,Cl atom is sp3 hybridised but due to lp−lp repulsions the angle decreases from 109∘−281 to 103∘ . Thus, the increasing order of bond angles is ClO2−<Cl2O<ClO2.