1.5 - solid structures

Question 1

Example of a simple molecular structure + 3 physical properties

Answer 1

• iodine
  -ice
  -low mp + bp
  -cannot conduct = no charge
  -insoluble unless they can form hydrogen bonds

Question 2

Outline the structure of ice

Answer 2

-hexagonal rings of 6 held together by hydrogen bonds.
-water molecules are held further apart
-ice less dense than water

Question 3

Definition of metallic bonding

Answer 3

-A lattice of cations, surrounded by a sea of delocalised electrons.
-With electrostatic forces between the electrons and the nucleus.

Question 4

4 Properties of metallic bonding

Answer 4

• High mp +bp = strong forces of attraction
• can conduct = sea of free electrons
• insoluble in water, no ions to attract polar nature of water
  -Malleable = layers slide over each other when forces are applied

Question 5

Examples of ionic solids

Answer 5

NaCl , CsCl
Giant lattices of negative and positive ions
Arranged in a way that the electrostatic repulsion is minimum and attraction is maximum.

Question 6

4 Properties of ionic solids

Answer 6

-Only conduct in liquid state -ions free to move
-soluble in water - ions are polar
-brittle, ions repeal and shatter
-high melting temp

Question 7

Physical properties of diamond

Answer 7

-cannot conduct = no free electrons
-High mp + bp = lots of strong covalent bonds
-insoluble
-hard = geometrical rigidity

Question 8

Structure of diamond

Answer 8

-Tetrahedral shape

Question 9

Physical properties of graphite

Answer 9

• can conduct = free electron between layers
  -high mp and bp
  -insoluble
  -low density = space between layers
  -soft = weak forces between layers are easily broken.