1a. Larger hydrocarbon molecules can be broken down into
more useful molecules by a process called
. To break the molecules down the hydrocarbons from oil are heated to
them and the hot vapours (gases) are passed over a heated
to make the process
, so it is more
efficient. Breaking compounds down by heat in this way is an example of a reaction known as a
(meaning 'breaking down with heat').
2. There are several types of hydrocarbons formed in this reaction and the products include
alkanes with no double bonds and
alkenes which have a carbon-carbon double bond.
3. C
nH
2n+2 is the general formula for the series of molecules known as
and
C
nH
2n is the general formula for the series of molecules known as
where n is the number of
atoms in the
.
4a.
is an example of an
.
4b.
is an example of hydrocarbon called an
, which is an
molecule because it has a carbon-carbon
bond.
4c.
is an example of an
.
4d.
is an example of an
, a type of hydrocarbon described as a
molecule because it has all
carbon-carbon bonds.