Homologous series Flashcards
What is a fuel?
Material such as coal,gas or oil that is burned to produce heat or power
How are fossil fuels formed?
Coal is formed from decayed plants
Gas and oil are formed from dead animals
How are fossil fuels extracted?
Mining
What is fractional distillation
Separation of a liquid mixture into fractions differing at boiling point
By means of distillation, typically using a fractionating column
What is combustion?
Process of burning something
Burning wood in a fire, presence of o2 and a lot of heat is produced
oxygen is one reactant, other is hydrocarbon
combustion reaction always produces CO2 and H20
Why do we use fuels?
For energy
What is the chemical definition of burning?
combustion. burning fuels must be an exothermic reaction as it gives of heat energy
What are fuels made up of?
Hydrocarbon molecules
What are homologous series?
A family of carbon-based compounds which are chemically similar and can have a general formulae written from the family
Describe the structure of alkanes
They are homologous series of hydrocarbons where all carbon to carbon bonds are single covalent bonds
Names all end in -ane
What is the general formula for alkane?
CnH2n+2
General formula for cycloalkanes and Alkenes
CnH2n
Describe cycloalkanes
Starts with cyclo and end in -ane
Are saturated so are carbon to carbon single covalent bonds
Describe alkenes
Names all end in -ene
All alkenes are unsaturated (double bond) at least 1 carbon to carbon double bond
How to name Alkanes
Longest chain of carbons and name if using prefixes and add -ane at the end
number the carbons do it the direction that will make the branch a low number
Name what carbon the branch is on
Use di for 2 branches, tri for 3
If two branches are coming off each other use ethane
How to name Alkenes
Longest chain of carbons containing double bond and name it using prefixes and add -ene at the end
Number the double bond making sure it’s in the direction to get a small number
Number where the branch is
3-methylBut-1-ene
What prefixes don’t exists in alkenes
methane and ethane
You can’t get a double bond with them
What are homologous series?
A homologous series is family of compounds with the same general formula and similar properties
what are Alkanes used for?
Fuels
What are cycloalkane used for?
used as a solvent
What are alkenes used for?
Polymers and alcohols
What decolourises bromine solution
A molecule that is unsaturated
Why do we use an addition reaction?
Used to test for unsaturation
Alkenes undergo addition reaction, hydrogen forming alkanes
Known as hydrogenation
Alkenes undergo addition reaction with halogens
forming dihaloalkanes
Alkenes undergo addition reaction, hydrogen forming water
forming alcohols, know as hydration
Name of group 1,7,8/0
Group 1 Alkali metal
Group 2 halogens
Group 8/0 Noble gas
