Transcript Document

Basic concepts
You need notes on;
Explain each type of formula and give examples for each
using hexane and pentene (for molecular, general,
structural, displayed, skeletal, 3-D, empirical)
Know the stem name for chains with 1-10 and 20 carbons.
Types of functional groups
Alkanes
Alkenes
Arenes
Alcohols
Halogenoalkanes
Carboxylic acids
Esters
Aldehydes
Ketones
Amines
Many different types of formula are used within chains and
rings dependent on what you are trying to show.
Each has its own use and you must be able to write any compound
in any of the formats stated.
For the purpose of showing each formula we will be looking at the
alkane propane, C3H8.
Molecular formula C3H8
This shows the number of each atom in
the molecule. It can be found from
empirical formula and molecular mass.
General formula CnH2n+2
This shows a ratio of the elements within
the compound for a homologous series
Displayed formula
H
H
H
H
C
C
C
H
H
H
H
This shows every atom and every bond in
the molecule; - is single bond; = a double
This is a shorthand form of the displayed
formula. Written without showing the
bonds
Structural formula
CH3CH2CH3
This shows only the carbon skeleton as
straight lines, each of which represents C-C
bond, plus any functional groups.
Skeletal formula
H
3-dimensional H
C
CH3
CH3
Empirical C3H8
This gives the best representation of the
shape of a molecule
Simplest ratio of the atoms
Do the same now for the ALKENE, propene
1) Molecular C3H6
3) Displayed
H
2) General CnH2n
H
H
H
C
C
C
H
4) Structural CH2CHCH3
H
5) Skeletal
7) Empirical CH2
CH2
6) 3-Dimensional
C
CH3
You must also be able to name various length carbon chains, the
following needs to be learnt.
1 carbon = meth
7 carbons = hep
2 carbons = eth
8 carbons = oct
3 carbons = prop
9 carbons = non
4 carbons = but
10 carbons = dec
5 carbons = pent
20 carbons = eicos
6 carbons = hex