Unit 1-Bonding

Question 1

Which type of chemicals will contain metallic bonding?

Answer 1

Metals

Question 2

Which type of chemicals will contain covalent bonding?

Answer 2

Non metals

Question 3

Which type of chemicals will contain ionic bonding?

Answer 3

Metals and non-metals

Question 4

What is an ionic bond?

Answer 4

Ionic bond is the electrostatic attraction between positive and negative ions.

Question 5

What is meant by an ionic lattice?

Answer 5

A lattice is a regular arrangement of ions where each positive ion is surrounded by negative ions and each negative ion is surrounded by positive ions.

Question 6

Explain the physical properties of ionic compounds:

1. melting point and boiling point
2. solubility (water molecules surround ions)
3. electrical conductivity

Answer 6

1. Ionic compounds have high melting and boiling points because strong ionic bonds must be broken in order to break down the lattice.
2. Tend to be soluble in water.
3. Ionic compounds conduct electricity only when molten or in solution.

Question 7

What is a covalent bond?

Answer 7

In a covalent bond, the shared pair of electrons is attracted to the nuclei of the two bonded atoms.

Covalent bonds are usually between non metals.

Question 8

Draw a diagram, showing all outer electrons, to represent a molecule of Arsenic Chloride, AsCl₃.

Answer 8

Question 9

What are the two types of covalent structures?

Answer 9

Covalent substances can form either molecular or network structures.

Question 10

Which elements exist as diatomic molecules?

Answer 10

HINFOClBr

Hydrogen, Iodine, Nitrogen, Fluorine, Oxygen, Chlorine and Bromine

Question 11

Name these shapes of molecules.

Answer 11

1. linear
2. angular
3. trigonal pyramidal
4. tetrahedral

Question 12

Explain the physical properties of covalent molecular compounds:

1. melting point and boiling point
2. solubility (water)
3. electrical conductivity

Answer 12

1. Covalent molecular substances have low melting and boiling points as only weak forces of attraction between molecules are being broken.
2. Covalent molecules tend to be insoluble in water but soluble in covalent type solvents.
3. Covalent molecules never conduct except carbon graphite.

Question 13

Explain the physical properties of covalent network compounds:

1. melting point and boiling point
2. solubility (water molecules surround ions)
3. electrical conductivity

Answer 13

1. Giant covalent network structures have very high melting and boiling points because the network of strong covalent bonds must be broken.
2. Covalent molecules tend to be insoluble in water but soluble in covalent type solvents.
3. Covalent molecules never conduct except carbon graphite.

Question 14

Describe the bonding in metals.

Answer 14

In metallic bonding, the outer electrons are delocalised (free to move). This produces an electrostatic force of attraction between the positively charged metal ions, and the negatively charged delocalised electrons.

Question 15

Explain the physical properties of metals.

1. Melting and boiling points
2. Conductivity of electricity

Answer 15

1. Metals are held together by strong forces and have high melting and boiling points.
2. The ability of metals to conduct electricity stems from their delocalised electrons. As these are free to move, an electrical current can flow through metallic materials.

Question 16

Which type of bonding matches each line in the table?

Answer 16

A= Covalent molecular

B = Covalent network

C = Ionic

D = Metallic

Question 17

Which type of bonding is represented by each diagram?

Answer 17

A = Metallic

B = Covalent molecular

C = Covalent network

D = Ionic