Alkanes + Alkenes Flashcards
what is alkane general formula
Cn H2n+2
What are the names of the first 5 alkanes
Methane
Ethane
Propane
Butane
Pentane
What does saturated mean
There are only single bonds between the carbon atoms
What is the product when halogens react with alkanes
Haloalkanes
Chlorine and bromine react with alkanes in the presence of what?
Ultraviolet light
The reaction between chlorine, bromine and an alkane is a substitution reaction. What happens in a substitution reaction?
- a hydrogen atom from the alkane is substituted with a chlorine or bromine atom
What do alkenes have that alkanes dont
A double bond
Why are alkenes an unsaturated molecule
they have a double bond, so they can make more bonds since the double bond can open up
What is the general formula for alkenes
Cn H2n
Show the displayed formula of propene
H H H H
l I I I
H — C — C = C
l I I
H H H
What is produced when halogens react with alkenes
Haloalkenes
What happens in a addition reaction
The C=C bond is split and a halogen atom is added to each of the carbons
Ethene + bromine —> dibromoethane
Show displayed formula
H H Br Br
I I I I
C = C + Br2 —> H - C - C -H
I I I I
H H H H
What is the reaction between bromin and alkenes often used for?
To test for carbon - carbon double bond
Describe and explain the experiment of bromine wate and an alkene?
- shake an alkene with orange bromine water until solution becomes colourless
- this is because bromine molecules which are orange react with alkene to make dibromoalkane which is colourless
