Bonding and physical properties

Question 1

How many types of crystal structures are there? What are the names of the different types of crystal structures?

Answer 1

There are four types of crystal structures:
1. Ionic crystal structure
2. Metallic crystal structure
3. Macromolecular crystal structure (giant covalent)
4. Molecular crystal structure

Question 2

What is the melting and boiling points of ionic crystal structures?

Answer 2

Ionic crystal structures have high melting and boiling points. This is because of the giant ionic lattice with strong electrostatic forces between oppositely charged ions

Question 2

What are the four main properties you look into when looking at the four types of crystal structures?
(ionic, metallic, macromolecular and molecular)

Answer 2

Properties: boiling and melting points, solubility in water, conductivity when solid and conductivity when molten

Question 3

What is the solubility of ionic crystal structures in water?

Answer 3

Ionic crystal structures are soluble in water - have generally good solubility

Question 4

What is the conductivity of ionic crystal structures when in a molten state?

Answer 4

Ionic crystal structures have good conductivity when molten , this is because the ions can move

Question 4

What is the conductivity of ionic crystal structures when in a solid state?

Answer 4

Ionic crystal structures have poor conductivity when in a solid state. This is because ions cannot move when fixed in a lattice

Question 5

What are the melting and boiling points of molecular (simple) structures?

Answer 5

Molecular structures have low melting and boiling points. This is because of weak intermolecular forces (van der Waals/hydrogen bonds) between molecules

Question 5

What is the general description of ionic crystal structures?

Answer 5

Ionic crystal structures are crystalline solids

Question 6

What is the conductivity of molecular (simple) structures when in a solid state?

Answer 6

Molecular structures have poor conductivity when in a solid state. This is because there are no ions to conduct and electrons are localised/fixed in place

Question 7

What is the solubility of molecular (simple) structures in water?

Answer 7

Molecular structures generally have poor solubility in water

Question 8

What is the conductivity of molecular (simple) structures when in a molten state?

Answer 8

Molecular structures have poor conductivity when in a molten state, because there are no ions

Question 9

What is the general description of molecular (simple) structures?

Answer 9

Molecular (simple) structures are mostly gases and liquids

Question 10

What are the melting and boiling points of macromolecular structures?

Answer 10

Macromolecular structures have high melting and boiling points. This is because of the many covalent bonds in the macromolecular structure which require a lot of energy to break the many strong bonds

Question 11

What is the solubility of macromolecular structures in water?

Answer 11

Macromolecular structures are insoluble in water

Question 12

What is the conductivity of macromolecular structures (DIAMOND/SAND) when in a solid state?

Answer 12

Diamond and sand are examples of macromolecular structures that poor conductivity when in a molten state. Their conductivity is poor because electrons cannot move, as they are localised

Question 13

What is the conductivity of macromolecular structures (GRAPHITE) when in a solid state?

Answer 13

Graphite are examples of macromolecular structures that have good conductivity when in a molten state. Their conductivity is good because there are free delocalised electrons between the layers of graphite

Question 14

What is the conductivity of macromolecular structures when in a molten state?

Answer 14

Macromolecular structures have poor conductivity when in a molten state

Question 15

What is the general description of macromolecular structures?

Answer 15

Macromolecular structures are solids

Question 16

What is the melting and boiling points of metallic structures?

Answer 16

Metallic structures have high melting and boiling points. This is due to the strong electrostatic forces between the positive ions and sea of delocalised electrons

Question 17

What is the solubility of metallic structures in water?

Answer 17

Metallic structures are insoluble in water

Question 18

What is the conductivity of metallic structures when in a solid state?

Answer 18

Metallic structures have good conductivity when in a solid state. This is because the delocalised electrons can move through the structure

Question 19

What is the conductivity of metallic structures in a molten state?

Answer 19

Metallic structures have good conductivity when in a molten state

Question 20

What is the general description of metallic structures?

Answer 20

Metallic structures are shiny metals. They are malleable as the positive ions in the lattice are identical so the planes of ions can easily slide over one another.

Additionally the attractive forces in the lattice are the same no matter what ions are adjacent