Naming branches chain Hydrocarbons

https://www.youtube.com/watch?v=k_PU5YlLGF4

What do branched chain hydrocarbons contain

A side chain / branch

How do we work out the name of this molecule

We identify the longest carbon chain, which is 7 (heptane)

Next look at number of carbon atoms in side chain, which is 1 carbon atom, side chain with one carbon atom is called a METHyl group

Then name position of methyl group on main carbon chain, by numbering carbon atomsl , numbering from right shows methyl group on carbon 3.

So this is called 3-methylheptane

What if there was 2 methyl groups on carbon 3

The molecle would be called 3,3-dimethylheptane, and this is 3,5- dimethylheptane

Name this molecule

Largest carbon chain is 5 atoms, so based on pentane.

Side chain with one carbon atom, so its called methyl

Main carbon chain has 5 atoms, so methyl group is on carbon 3

This molecule is called 3-methylpentane

What if we have 2 side chains that are not the same.

Side chains are listed alphabetically.

Longest chain is 8 carbon atoms, so octane

Theres a one carbon side chain, methyl group on the bottom

2 carbon side chain on the top, ethyl group

Identify positions of side chain , methyl group is on carbon 3, ethyl group on carbon 5

so its called 5-ethyl-3-methyloctane

Name this molecule

Longest chain has five carbon atoms, and carbon double bond is between c2 and c3, so based on pent-2-ene

Methyl group on carbon 3, so molecule is called 3-methylpent-2-ene