3.5 Describe the substitution reaction of methane with bromine to form bromomethane in the presence of UV light.

(Taken directly, word for word (because I am extremely lazy right now) from Hannah Help Chemistry)

In UV light bromine and methane will form bromomethane:

CH₄  +  Br₂ >CH₃Br  +  HBr

What has happened in this reaction is a bromine has taken the place of a hydrogen (substitution.)

3.4 Recall the products of the complete and incomplete combustion of alkanes

Complete combustion of alkanes will give you carbon dioxide and water

Incomplete combustion will give you carbon monoxide and water

3.3 Draw displayed formulae for alkanes with up to five carbon atoms in a molecule, and name the straight-chain isomers

All you need to remember when drawing displayed formulas for alkanes is that every carbon is bonded to two hydrogens (usually draw them one on top and one below) and there are two hydrogens on the end of the whole thing.

Below is the displayed formula for
1. Methane


2. Ethane
 

3. Propane


4. Butane


5. Pentane

3.2 Recall that alkanes have the general formula CnH2n+2

If you see the post tagged 3.1, a general formula is a formula that all members of a homologous series (in this case, the alkanes) will fit.

Basically (in every single alkane) for every carbon atom there will be twice the amount of hydrogen plus two.
- E.g.: 2 carbons
-         2(2) + 2 hydrogens = 6 hydrogens