Question

Predict the correct order of repulsion among the following:

• A. $\text{lone pair - lone pair > lone pair - bond pair > bond pair - bond pair}$
• B. $\text{lone pair - lone pair > bond pair - bond pair > lone pair - bond pair}$
• C. $\text{bond pair - bond pair > lone pair - bond pair > lone pair - lone pair}$
• D. $\text{lone pair - bond pair > bond pair - bond pair > lone pair - lone pair}$

Answer 1

The correct option is A $\text{lone pair - lone pair > lone pair - bond pair > bond pair - bond pair}$

The decreasing order of the repulsion between electron pairs is

$\text{lone pair - lone pair > lone pair - bond pair > bond pair - bond pair}$

Lone pair is localised on the central atom and is attracted to one nucleus. Each bond pair is shared between two atoms and thus attracted by two nuclei. Lone pair of electrons occupy more space than the bond pair of electrons, hence, they experience more repulsion.
Thus, option (a) is a correct answer.