Unit 1.5 - Comparing Typical Solid Structures

Question 1

State the type of substance, constituent particles and give an example of:

1) Giant Molecular
2) Ionic
3) Molecular crystals

Answer 1

1) Group IV, atoms, diamond and graphite.
2) Metal/non-metal compound, ions, NaCl and CsCl.
3) Non-metal element/ 2 electronegative elements, molecules, iodine.

Question 2

Describe the bonding of a solid in:

1) Giant molecular
2) Ionic
3) Molecular crystals

Answer 2

1) Atoms linked by strong covalent bonds.
2) Attraction of +ve for -ve ions to form strong ionic bonds.
3) Strong covalent hold atoms together within separate molecules, separate molecules held by weak Van der Waals bonds.

Question 3

Describe the volatility and its state at room temperature for the following:

1) Giant molecular
2) Ionic
3) Molecular crystals

Answer 3

1) Non-volatile - very high m.p, solid.
2) Non-volatile - high m.p, solid.
3) Volatile - low m.p, volatile liquids or gases.

Question 4

Describe the hardness and conductivity of:

1) Giant molecular
2) Ionic
3) Molecular crystals

Answer 4

1) Very hard and brittle, non-conductors except graphite.
2) Hard and brittle, non-conductors when solid but good when molten.
3) Soft, non-conductors in solid, liquid or in aqueous solution.

Question 5

Describe the solubility of:

1) Giant molecular
2) Ionic
3) Molecular crystals

Answer 5

1) Insoluble in all solvents.
2) Soluble in polar solvents, insoluble in non-polar solvents.
3) Insoluble in non-polar solvents.