SHAPES OF MOLECULES

Question 1

2 Electron pairs around the central atom shape and angle

Answer 1

1.Linear

180

Question 2

3 Electron pairs around the central atom no lone pairs

Answer 2

1. Trigonal planar

120

Question 3

3 Electron pairs around the central atom one lone pair

Answer 3

1.Bent/non-linear

119

Question 4

4 Electron pairs around the central atom no lone pairs

Answer 4

1. Tetrahedral

109. 5

Question 5

4 Electron pairs around the central atom one lone pair

Answer 5

1.Trigonal pyramidal

107

Question 6

4 Electron pairs around the central atom two lone pairs

Answer 6

1. Bent/non-linear

104. 5

Question 7

5 Electron pairs around the central atom no lone pair

Answer 7

1.Trigonal bipyramidal

90 and 120

Question 8

5 Electron pairs around the central atom one lone pair

Answer 8

1. Seesaw

87 and 102

Question 9

5 Electron pairs around the central atom two lone pairs

Answer 9

1. Distorted T

87. 5

Question 10

6 Electron pairs around the central atom no lone pair

Answer 10

1.Octahedral

all bond angles 90

Question 11

6 Electron pairs around the central atom one lone pair

Answer 11

1. square pyramidal

81. 9 and 90

Question 12

6 Electron pairs around the central atom two lone pairs

Answer 12

1.Square planar

90

Question 13

How do you predict the shape of a molecule

Answer 13

1. Find the central atom
2. Work out the numbers in the outer shell of the central atom (use periodic table)
3. Use the molecular formula to tell you how many atoms the central atom is bonded to- this will helps you work out how many electrons are shared with the central atom
4. Add up the electrons and divide by 2 to find the number of electron pairs on the central atom. If you have an ion account for its charge
5. Compare the number of electron pairs with the number of bonds to find the number of lone pairs
6. Work out the shape