Molecular Shapes

Question 1

what is the VSPER Theory

Answer 1

valence shell electron pair repulsion theory

states that valence shell electron pairs will repel themselves as fa apart as possible in the 3D of space

the shape adopted by a simple molecule or ion is that which keeps repulsive forces to a minimum

Question 2

bond pair repulsions angles in molecules without lone pairs

Answer 2

1 or 2 bond pairs - linear - 180 degrees
3 bond pairs - trigonal planar - 120 degrees
4 bond pairs - tetrahedral - 109.5 degrees

all bond pair bond pair repulsions are equal

Question 3

order of repulsive power between bonds

Answer 3

LP - LP > BP - LP > BP - BP

Question 4

how are the angles between lone pairs and bond pairs changed

Answer 4

lone pairs have greater repulsive power than bond pairs so their presence will affect (increase) the angles of the bonds as they push the bond pairs away.

Question 5

bond pair and lone pair repulsions angles in molecules with lone pairs

Answer 5

3 BP and 1 LP
angle is 107 degrees
shape is pyramidal

2 BP and 2 LP
angle is 104.5 degrees
shape is bent