Shapes of Molecules

Question 1

valance shell electron pair repulsion theory

Answer 1

shape depends on the number pf electrons around the central atom
each pair of electrons repel against other pairs so take up positions as far as apart as possible to minimise repulsion

Question 2

do lone pairs or bond pairs have higher repulsion and why

Answer 2

lone pairs are higher in concentration so have greater repulsion as they are attracted to only one nucleus

Question 3

how much does the angle decrease per lone pair

Answer 3

2.5 degrees

Question 4

order of repulsion for lone pairs and bond pairs

Answer 4

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

Question 5

shape and angle for:
2 bonding
0 lone

Answer 5

linear

180

Question 6

shape and angle for:
3 bonding
0 lone

Answer 6

trigonal planar

120

Question 7

shape and angle for:
2 bonding
1 lone

Answer 7

bent

118

Question 8

shape and angle for:
4 bonding
0 lone

Answer 8

tetrahedral

109.5

Question 9

shape and angle for:
3 bonding
1 lone

Answer 9

trigonal pyramid

107

Question 10

shape and angle for:
2 bonding
2 lone

Answer 10

bent

104.5

Question 11

shape and angle for:
5 bonding
0 lone

Answer 11

trigonal bipyramid

120 and 90

Question 12

shape and angle for:
4 bonding
1 lone

Answer 12

see-saw

119 and 89

Question 13

shape and angle for:
3 bonding
2 lone

Answer 13

trigonal planar 120

T-shape 89

Question 14

shape and angle for:
6 bonding
0 lone

Answer 14

octahedral

90

Question 15

shape and angle for:
5 bonding
1 lone

Answer 15

distorted square pyramid

89

Question 16

shape and angle for:
4 bonding
2 lone

Answer 16

square planar

90

Question 17

how to explain shape

Answer 17

state number of bonding and lone pairs of electrons
- pairs of electrons repel against each other to positions of minimal repulsion
- if there are no lone pairs, the bonding pairs repel equally
- lone pairs repel more than bonding pairs
state actual shape and bonding angle