Covalent Bonding

Question 1

What is a covalent bond?

Answer 1

The strong attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 2

How many covalent bonds do
1. Oxygen 
2. Nitrogen 
3. Carbon
Form?

Answer 2

1. 2
2. 3
3. 4

Question 3

What is a dative covalent bond?

Answer 3

A shared pair of electrons provided by 1 of the bonded atoms only

Question 4

What are the 3 limitations to the octet rule?

Answer 4

1. There may not be enough space in the outer level for 8
2. There may not be enough electrons available
3. There may be space for more than 8 electrons

Question 5

What are the regions of negative charge in an electron pair?

Answer 5

Single or multiple covalent bonds

Lone pairs of electrons

Question 6

How does the shape of molecule or molecular ion arise?

Answer 6

The different types and number of negative regions in outer shell of the central atom

Question 7

What do the regions of negative charge do?

Answer 7

They repel each other as far as possible

Question 8

What is the name of the shape, size of bond angle and an example of a molecule with 2 covalent bonds?

Answer 8

Shape= linear
Bond angle= 180 degrees
Example= CO2

Question 9

What is the name of the shape, size of bond angle and an example of a molecule with 3 covalent bonds?

Answer 9

Shape= trigonal planar
Bond angle= 120 degrees
Example= BF3

Question 10

What is the name of the shape, size of bond angle and an example of a molecule with 4 covalent bonds?

Answer 10

Shape= tetrahedral
Bond angle= 109.5
Example= CH4

Question 11

What is the name of the shape, size of bond angle and an example of a molecule with 6 covalent bonds?

Answer 11

Shape= Octahedral
Bond= 90
Example= SF6

Question 12

What is the difference between a lone pair and a covalent bond?

Answer 12

A lone pair has a greater repulsion that any bonded pairs therefore reduces the bond angle

Question 13

What does a lone pair have a greater repulsion?

Answer 13

They fill a smaller space than any bond pair and have a higher density of negative charge

Question 14

What is the name of the shape, bond angle and an example of a molecule with 3 single bond pairs and 1 lone pair of electrons?

Answer 14

Shape: pyramidal
Bond angle: 107
Example: ammonia

Question 15

What is the name of the shape, bond angle and an example of a molecule with 2 single bond pairs and 2 lone pairs of electrons?

Answer 15

Shape: non-linear
Bond angle: 104.5
Eg: water

Question 16

How much does each additional lone pair reduce the bond angle by?

Answer 16

2.5 degrees