Question

Use VSEPR theory to decide which one of the following molecules and ions will definitely have at least one 90° bond angle in it. (In each case except water, the central atom is the first one in the formula.)(A) AlCl4-(B) NH3(C) PCl5(D) CO2(E) H2O

Answer 1

Answer:

(C) PCl₅

Explanation:

(A) AlCl₄⁻

The central atom has 4 bond pairs and 0 lone pair. Hybridization is sp³. The geometry is tetrahedral which has an angle of 109.5°.

(B) NH₃

The central atom has 3 bond pairs and 1 lone pair. Hybridization is sp³. The geometry is pyramidal which has an angle of approximately 107.5°.

(C) PCl₅

The central atom has 5 bond pairs and 0 lone pair. Hybridization is sp³d². The geometry is trigonal bipyramidal in which the equatorial bonds has an angle of 120° and axial bond has an angle of 90°.

(D) CO₂

The central atom has 4 bond pairs and 0 lone pair. Hybridization is sp. The geometry is linear which has an angle of 180°.

(E) H₂O

The central atom has 2 bond pairs and 2 lone pairs. Hybridization is sp³. The geometry is bent shape which has an angle of approximately 105.5°.