Topic 6A: Introduction to organic chemistry Flashcards
what is a hydrocarbon
a compound containing only carbon and hydrogen atoms
what is the empirical formula
the simplest whole number ratio of atoms of each element in a compound
what is the molecular formula
the true number of atoms of each element in a compound
what is the general formula
All members of a homologous organic series follow the general formula. For example, alkanes have the general formula CnH2n+2
what is the structural formula
shows the structural arrangement of atoms within a molecule
butane - CH3 CH2 CH2 CH3
what is the displayed formula
shows the structural arrangement of atoms within a molecule
what is the skeletal formula
shows the bonds in a compound between the carbon atoms only
what are all the prefixes for carbon atoms from 1 - 10
1 - meth-
2 - eth-
3 - prop-
4 - but-
5 - pent-
6 - hex-
7 - hept-
8 - oct-
9 - non-
10 - dec-
define homologous series
a group of compounds which have the same functional group and general formula
what are three features of a homolgous series
- all have the same functional group
- all have the same general formula
- each compound in the series differs by a CH2 unit
define functional group
a group of atoms responsible for the characteristic reactions of a particular compound
what are the different homologous series
(10)
SERIES SUFFIX/PREFIX EXAMPLE
Alkanes -ane Propane (CH3CH2CH3)
Branched alkanes Alkyl- Methylpropane (CH3C(CH3)CH3)
Alkenes -ene Propene (CH3CH=CH2)
Halogenoalkanes Fluoro- / Chloro- / Bromo- / Iodo- Chloroethane (CH3CH2Cl)
Alcohols -ol Ethanol (CH3CH2OH)
Aldehydes -al Ethanal (CH3CHO)
Ketones -one Propanone (CH3COCH3)
Carboxylic acids -oic acid Ethanoic acid (CH3COOH)
Esters Alkyl- oate Ethyl ethanoate (CH3COOCH2CH3)
Amides -amide Ethanamide (CH3CONH2)
what are the different reactions
(7)
-addition
-elimination
-substitution
-oxidation
-reduction
-hydrolysis
-polymerisation
what is an addition reaction
joining two or more molecules together to form a larger molecule
what is an elimination reaction
when a small group of atoms breaks away from a larger molecule to form a c=c bond
what is a substitution reaction
when one species is replaced by another
what is a oxidisation reaction
a species gains oxygen and loses at least on electron
what is a reduction reaction
a species looses oxygen and gains of electrons
what is a hydrolysis reaction
breaking the bonds of a molecule by a reaction with water
what is a polymerisation reaction
joining together lots of small/simple monomers to form giant molecules (polymer)
what is an isomer
molecules with the same molecular formula but different arrangement of atoms within the molecule
what are the two types of isomers
- structural isomers
- stereoisomers
what are the three types of structural isomers
- chain isomers
- positional isomers
- functional group isomers
how are chain isomer different
- differ in the carbon skeleton arrangement ( eg straight chain vs branched chain)
positional isomers
- the functional group is attached at different carbon atoms
functional group isomers
- the atoms form different functional groups
what is stereoisomerism
molecules which are connected in the same way but have different spatial arrangements of atoms
what are the two types of stereoisomerism
- e/z isomerism
- cis trans isomerism
what is the difference between e isomer and z isomer
- e isomer means the functional groups are on opposite sides
- z isomerism is when the functional group is on the same sideH Cl H H
l l l l
C = C C = C
l l l l
Cl H Cl Cl
E Z
Br Cl
l l
C = C
l l
F H
Z isomerism - as Br and Cl have a higher atomic number that F and H, so they have a higher priority
the atoms with a higher priority are on the same side so this is a z isomer
what is the difference between cis / trans isomerism and E/Z isomerims
- cis and trans can only be used when there are hydrogen atoms to compare the other two groups
