Hydrocarbons are mainly used as fuel. They consist only of hydrogen and carbon, each carbon has 4 covalent bonds attached. Each hydrogen has only 1 covalent bond attached.
Crude oil contains both alkanes and alkenes (although mostly alkenes). they have different properties and its all down to their structure.
- have chains of carbon atoms with one or more double covalent bonds. (double covalent bond - atoms sharing two pairs of electrons, a double bond counts as 2 of a carbon atoms 4 attached bonds)
- unsaturated hydrocarbons - double bonds can open up and let things join on.
- decolourise bromine water - form bonds with bromine (bromine goes clear)
- formula for all alkenes containing one double bond = CnH2n
- more reactive - due to double bond which will open up and attach to other things.
- form polymers by a double bond opening up and 'holding hands' in a long chain.
- burn with smoky flame producing soot (carbon)
Ethene C2H4 …