Bonding

Question 1

Define electronegativity [1]

Answer 1

[1] Atom’s ability to attract the lone pair of electrons

Question 2

Why is the C-Cl bond polar? [2]

Answer 2

[1] Cl is highly electronegative

[2] so the electron density is not symmetrical

Question 3

Why is CCl4 non polar? [2]

Answer 3

[1] It is a symmetrical molecule

[2] So dipoles cancel out

Question 4

Whatcauses VdW forces between non polar molecules? [3]

Answer 4

[1] Random movement of electrons

[2] Induces a dipole in another molecule

[3] Dipoles in different molecules attract

Question 5

In terms of intermolecular forces, why does CBr4 have a higher boiling point than CHBr3 [3]

Answer 5

[1] CBr4 have VdW forces

[2] CHBr3 have VdW forces and permanent dipole-dipole forces

[3] CBr4 have stronger intermolecular forces

Question 6

Ionic bonding properties

Answer 6

Electrostatic attraction between two oppositely charged ions.

Soluble as polar.

Conducts electricty when molten or dissolved in solution as ions are free to move.

High m.p

Question 7

Simple molecular covalent properties

Answer 7

Electrostatic attraction between sharing of outer electrons in NM.

Lower b.p as weak intermolecular forces.

Solubility dependant on polarity.

Cannot conduct electricity.

Brittle due to weak intermolecular forces.

Question 8

Properties of graphite

Answer 8

Carbon bonded 3 times with 4th electron delocalised.

Can carry charge.

Layers slide over eachother easily due to weak inbetween forces.

High b.p

Low density layers

Insoluble

Question 9

Graphene properties

Answer 9

Can conduct electricity.

Insoluble.

2D so less resistance.

High mp and bp

Question 10

Diamond properties

Answer 10

Carbon bonded 4 times.

Cannot conduct electricity due to no delocalised electrons.

Can conduct heat well.

Insoluble.

High bp

Question 11

Metallic properties

Answer 11

Electrostatic attraction between metal ions and delocalised electron.

More positive the metal = higher the bp

Good thermal and electrical conducters.

Insoluble

Question 12

Ice properties

Answer 12

Polar bond with strong H bonds

Water into ice becomes less dense as H bonding pushed molecules futher apart