free 10 marks

Question 1

Why do ionic bonds have a high melting MP/BP

and why are they hard to break

Answer 1

High MP - strong electrostatic forces of attraction between oppositely charged ions, require a lot of energy to break

Question 2

Why do small molecule (covalent) bonds have a low MP/BP and why are they hard to break

Answer 2

Low MP/BP, strong covalent bonds but weak IMF between molecules, which do not require a lot of energy to overcome

Question 3

Why do Giant Covalent have such high BP/MP (e.g.: diamond, graphite)

Answer 3

High MP - strong covalent bonds which require a lot of energy to break

Question 4

Metals BP/MP

Answer 4

High MP - strong electrostatic forces of attraction between positive metal ions and delocalised electrons, requires a lot of energy to break

Question 5

Conducts electricity ionic

Answer 5

Solid does not conduct - ions are not free to move and carry a charge. Molten/dissolved does conduct as ions are free to move and carry a charge.

Question 6

Conducts electricity small molecule

Answer 6

Does not conduct electricity as the substance does not contain any charged particles

Question 7

Conducts electricity Metals

Answer 7

Positive ions and “sea” of delocalised electrons, which are free to carry a charge.

Question 8

Conducts electricity giant covalent (Diamond)

Answer 8

Each C atom is bonded to 4 other C atoms and so does not conduct as there are no free electrons to carry a charge.

Question 9

Conducts electricity giant covalent (Graphite)

Answer 9

Each C atom is bonded to 3 other C atoms and so there is 1 delocalised electron per C atom to carry a charge

Question 10

Hardness Ionic

Answer 10

Lattice structure, strong electrostatic forces between oppositely charged ions in all directions.

Question 11

Hardness giant covalent (diamond)

Answer 11

Giant lattice structure, strong covalent bonds in all directions

Question 12

Hardness giant covalent (Graphite)

Answer 12

Soft - Hexagonal sheets of carbon atoms of strong covalent bonds, but weak IMF between layers, which do not require a lot of energy to overcome

Question 13

Hardness metals (Pure metal)

Answer 13

Malleable - ordered layers of metal atoms which can easily slide past each other

Question 14

Hardness metals (Alloy)

Answer 14

Hard - metal atoms of different sizes can distorted/disrupted layers, which cannot slide past each other