Slides in this set
· Crude oil is made up of hydrocarbons, which are
molecules made of only hydrogen and carbon.
· There are three main types of hydrocarbon, and the two
needed for the exam are alkanes and alkenes.
· Alkanes are saturated, and alkenes are unsaturated.
This means that alkenes have some double bonds, so
they can react easily, but alkanes have only single
ALKANES AND ALKENES
· Because alkanes have only single bonds, all
the possible bonds are filled. This gives
alkanes the general formula
· As alkenes have a double bond, not all the possible
bonds are filled, giving alkenes the general formula
THE TEST FOR UNSATURATION
· We can do a simple test to see if there are any alkenes in
· If you add bromine water to a hydrocarbon containing
alkenes, it changes from orange to colourless*. If there
are only alkanes, it stays orange.
* - DON'T say it goes clear; that only means it's
see through, like the coloured wrappers on
Quality Streets.…read more
· Crude oil is made of different lengths `fractions' - of
hydrocarbon molecule. Some may have only five atoms,
but some have hundreds!
· We can separate different fractions using `fractional
· Because short molecules are more useful, we need a
way to split up longer ones.
· The method we use is called `cracking'.…read more