hydrocarbons as level chemistry
TRANSCRIPT
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 :