hydrocarbons as level chemistry

AS level Chemistry Project by –

Aalekh Patel

- basically means the substance acquiring

the carbon element and the hydrogen

element together. They are also known as

Organic.

There are lots of them.

90% + of known compounds are Organic

Carbon forms chains to create new

substances.

Hydrocarbons containing only single

covalent bonds are known as Alkanes.

Ex: CH4 – methane – natural gas.

CH3CH2CH3 – propane – fuel in portable

stoves.

Methane CH4 CH4

Ethane C2H6 CH3CH3

Propane C3H8 CH3CH2CH3

Butane C4H10 CH3CH2CH2CH3

Pentane C5H12 CH3CH2CH2CH2CH3

Hexane C6H14 CH3CH2CH2CH2CH2CH3

Heptane C7H16 CH3CH2CH2CH2CH2CH2CH3

Octane C8H18 CH3CH2CH2CH2CH2CH2CH2CH3

Nonane C9H20 CH3CH2CH2CH2CH2CH2CH2CH2CH3

Decane C10H22 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3

A group of compounds in which there is a

constant increment of change in molecular

structure from one compound in the series

to the next.

The alkanes differ by one CH2 group each

time

CnH2n+2

Substituent – an atom or group of atoms

that can take the place of a hydrogen atom

on a parent hydrocarbon molecule.

Parent chain – the longest carbon chain.

May not always be written in a straight line

on paper.

CH3 – methyl

CH3CH2 – ethyl

CH3CH2CH2 – propyl

Alkyl group = alkane – 1 H

Name = - ane + yl

What would CH3CH2CH2 CH2 be called?

Ans - Butyl

1. Find the longest chain of carbons. This

is the parent chain

2. # the carbons on the parent chain.

Starting with the end that will give the

substituents the smallest numbers

3. Add #s to the names of the substituent

groups to identify their positions on the

chain.

4. Use prefixes to indicate if a group appears more than once. • Di – 2• Tri – 3• Tetra – 4• Penta – 5

5. List the names of the alkyl substituents in alphabetical order (ignore prefixes when alphabetizing.)

6. Use proper punctuation• Commas separate #s from #s• Hyphens separate #s from words

Alkenes – Hydrocarbons containing carbon-

carbon double covalent bonds.

Unsaturated compounds – Organic compounds

that contain double or triple C-C bonds.• They have fewer than the number possible of Hydrogen

in their structure.

Saturated hydrocarbons – alkanes – all single

bonds.• Have the maximum number of hydrogen possible.

1. Find the longest chain in the molecule

THAT CONTAINS the double bond.

(parent)

2. Root name from alkane -ane +ene

3. # the chain so that the double bond

gets the lowest possible #. (# is listed in

the name)

Substituent is named just like alkanes.

Alkynes – hydrocarbons containing C-C

triple bonds

Named just like alkenes, -yne instead of –

ene

Cyclic hydrocarbons – compounds that

contain a hydrocarbon ring.

Aliphatic compounds – do not contain rings

Aromatic compounds – compounds in

which the bonding is like that of benzene.

Use the prefix cyclo- before the parent

name.

Example : Cyclohexane (C6H14)

Cyclopentane (C5H12)

Structural isomers – compounds that have

the same molecular formula but different

molecular structures.

For example :