Give the approximate bond angle for a molecule with tetrahedral electron geometry and trigonal pyramidal molecular geometry.
A) 180°
B)

Question

Give the approximate bond angle for a molecule with tetrahedral electron geometry and trigonal pyramidal molecular geometry.
A) 180°
B) <180°
C) <109.5°
D) 109.5°
E) <120°

Quizplus · Accepted Answer

The tetrahedral electron geometry implies that there are four electron domains around the central atom. In this case, the four electron domains are bonding pairs and a lone pair. The lone pair occupies more space than the bonding pairs, so the repulsion between the lone pair and the bonding pairs pushes the bonding pairs closer together, resulting in a bond angle less than the ideal tetrahedral angle of 109.5°.

Since the molecular geometry is trigonal pyramidal, one of the bonding pairs is replaced by the lone pair, resulting in a bond angle less than 109.5° but greater than the ideal angle for a trigonal planar molecule of 120°. Therefore, the best choice is C: <109.5°.

Give the Approximate Bond Angle for a Molecule with Tetrahedral