Question

Select the correct code for the following repulsion orders, according to VSEPR theory
(I) lone pair-lone pair $>$ lone pair-bond pair
(II) lone pair-bond pair $>$ bond pair-bond pair
(III) lone pair-lone pair $>$ bond pair-bond pair
(IV) lone pair-bond pair $>$ lone pair-lone pair

• A. $I,II$ and $III$
• B. $II$ and $IV$
• C. $I,II$ and $IV$
• D. All

Answer 1

The correct option is A $I,II$ and $III$

According to the $VSEPR$ theory, lone pairs of electrons occupy more space than bonding pairs. As a consequence, this is an order of the magnitude of repulsion.

$lp-lp>lp-bp>bp-bp$

• Greatest repulsion is between 2 lone pairs.
• Followed by repulsion between one lone pair and one bonding pair.
• The weakest repulsion is between 2 bonding pairs, the magnitude of repulsion between bonding pairs of electrons depends on the $EN$ difference between a central atom and the other atoms.