Structure & Bonding

Question 1

3 ways formation of chemical bonds can be done?

Answer 1

Transferring electrons, sharing electrons or forming a metal lattice

Question 2

What type of structure are ionic compounds?

Answer 2

Giant ionic crystal lattice structure

Question 3

Why do giant ionic crystal lattices have high boiling and melting points?

Answer 3

The ions are held together by strong ionic bonds which require a lot of energy to overcome

Question 4

Why are ionic compounds soluble in water?

Answer 4

Water molecules can attract the ions and pull them away from each other, disrupting the giant ionic crystal lattice structure, resulting in the ions separating and dissolving in the solution.

Question 5

Why are ionic compounds good conductors of electricity in molten/aqueous state but not so in solid state?

Answer 5

• In solid state, the ions are held tightly in fixed positions and cannot move
• In molten/aqueous state, ions are able to move freely and act as mobile charge carriers to conduct electricity

Question 6

Name the 3 covalent compounds in giant molecular structure that you need to know

Answer 6

Diamond, graphite, silicon dioxide

Question 7

Describe the solubility of covalent compounds in simple molecular structure.

Answer 7

Most are soluble in organic solvents but most are insoluble in water

Question 8

Why are covalent compounds in simple molecular structure poor conductors of electricity?

Answer 8

Electrons of their ions are involved in sharing and there are no free moving electrons to conduct electricity

Question 9

Diamond is comprised of carbon atoms being held together by strong single covalent bonds. Each carbon atom is bonded with __ other carbon atoms to attain a full valence shell, forming a _____________ structure.

Answer 9

4; tetrahedral

Question 10

Graphite is made up of ________ layers of carbon atoms. Each layer of graphite has a carbon atom that is covalently bonded to ____ other carbon atoms to form ________________.

Answer 10

flat; 3; regular hexagonal rings

Question 11

Graphite is a unique covalent compound in giant molecular structure. How so?

Answer 11

• It has weak intermolecular forces of attraction between the layers. Layers can slide over each other easily.
• Graphite is a good conductor of electricity. Each carbon atom has one valence electron that is not used to form covalent bonds. This electron is delocalised and is free to move and act as mobile charge carrier, hence can conduct electricity.

Question 12

In silicon dioxide, each silicon atom forms covalent bonds with ___ oxygen atoms while each oxygen atom forms covalent bonds with ___ silicon atoms.

Answer 12

4; 2