Summary Edexcel iGCSE Chemistry Revision Notes on Organic Chemistry

Organic Compounds
General formula : an algebraic formula that can describe any member

of a family of compounds (e g . .
alkenes >
-
CnHan
Empirical formula : the simplest whole number ratio of atoms of each element

in a compound (e g
. .

(He >
-
CH2)
Molecular formula : the actual number of atorms of each element in a

Molecule (e g
.
.

(He)
Structural formula :
shows the arrangement of atoms carbon by carbon
,
with the attached hydrogens (e g .

CH2CH2)
Displayed formula : shows how all the atoms are arranged and all the




( (
bonds between them e H
gH
. -



,
C = C
-
1 H
Homologous Series : a group of compounds that can all be represented

by the same general formula
Molecules in a momologous series contain the same functional group
↳)
functional group : a group of atoms that determine now a compound typically
reacts

compounds in a homologous series often react in Similar ways



~
of carbons - penen, -




Homologous Series
A
lan es
Suffix
-
and
ISOMERS
Alkenes -
ene Isomers : Molecules that have the same

AICONOLS Ol molecular formula but their atoms
-




are arranged differently
Iso they have different structural formwas


SIMILARITIES :



E
H

HH HH
C H
&
their chemical properties



F
111 H - -




H C C H ISOMERS ↳ the

I
c c way they react
- - - - -




·
I 1 I H H
HHH H I I
H -
C -
C -
C -
H DIFFERENCES :
butane A

it it it ·
physical properties
both molecules have the me+my propane ↳ (e g . .

boiling point)
formula C+ H10



functional groups in different places




S
H HH H H HH H The functional group (the double bond =

1 I I 1
H -
c =
c - - -
HH - -
c = - -
H functional group for alkenes) is attached

it H it to a different carbon


but(-1-Jene but-2-ene Different physical properties



CRUDE OIL
Crude oil : a mixture of substances hydrocarbons)
(mainly