Question

Predict the correct order among the following:

• A. lone pair - lone pair > lone pair - bond pair > bond pair - bond pair
• B. lone pair - lone pair > bond pair - bond pair > lone pair - bond pair
• C. bond pair - bond pair > lone pair - bond pair > lone pair - lone pair
• D. lone pair - bond pair > bond pair - bond pair > lone pair - lone pair

Answer 1

Answer: (A)

lone pair - lone pair > lone pair - bond pair > bond pair - bond pair

The decreasing order of the repulsion between electron pairs is

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

Lone pair is localized 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.