MODULE 2

Question 1

Linear

a) bond angle(s)
b) number of pairs
c) example molecule and structure

Answer 1

a) 180
b) 2 bond pairs
c) BeCL2
d) regular molecule

Question 2

Trigonal Planar

a) bond angle(s)
b) number of pairs
c) example molecule and structure

Answer 2

a) 120
b) 3 bond pairs
c) BF3

Question 3

Tetrahedral

a) bond angle(s)
b) number of pairs
c) example molecule and structure

Answer 3

a) 109.5
b) 4 bond pairs
c) CH4

Question 4

Trigonal pyramidal

a) bond angle(s)
b) number of pairs
c) example molecule and structure

Answer 4

a) 120, 90
b) 5 bond pairs
c) PF5

Question 5

Octahedral

a) bond angle(s)
b) number of pairs
c) example molecule and structure

Answer 5

a) 90
b) 6 bond pairs
c) SF6

Question 6

Pyramidal

a) bond angle(s)
b) number of pairs
c) example molecule and structure

Answer 6

a) 107
b) 3 bond pairs 1 lone pair
c) NH4

Question 7

Non linear

a) bond angle(s)
b) number of pairs
c) example molecule and structure

Answer 7

a) 104.5
b) 2 bond pairs, 2 lone pairs
c) H2O

Question 8

Electron repulsion theory

Answer 8

“the shape adopted is the one which keeps repulsive forces to a minimum”

Question 9

the order of repulsive power

Answer 9

lone pair–lone pair > lone pair–bond pair > bond pair– bond pair

Question 10

oxidation number rules

atom Na
cation Na in Na+
anion Cl in Cl-

Answer 10

“the number of electrons which must be added or removed to become neutral”

atom Na = 0
cation Na = +1
anion Cl = -1

Question 11

oxidation number rules

molecules

Answer 11

“the sum of the oxidation number must add up to zero”

Question 12

oxidation number rules

complex ions

Answer 12

“the sum of the oxidation numbers add up to the charge on the ion”