C7-Organic Chemistry

Created by

Elle Roberts

Cards (20)

what is a hydrocarbon?
any compound formed from carbon and hydrogen atoms only
what is the general formula for alkanes?
CnH2n+2
whats a homologous series?
a group of organic compounds that react in a similar way
what are alkanes?
saturated compounds
whats the formula for methane?
CH4
whats the formula for ethane?
C2H6
whats the formula for propane?
C3H8
whats the formula for butane?
C4H10
what are some properties of a small carbon chain?
less viscous
more volatile=lower boiling point
more flammable
whats the equation for combustion?
hydrocarbon + oxygen=carbon dioxide + water
what happens to carbon and hydrogen during combustion?
oxidisation
how is crude oil formed?
remains of plankton that died millions of years ago that was buried in mud
what does fractional distillation do?
separates hydrocarbon fractions
what are the steps of fractional distillation?
-oil is heated until its turned to gas which enters a fractionating column
-fractionating column has a temperature gradient. hot at the bottom, cold at the top
-longer hydrocarbons have high boiling points, condense back into liquids and drain out the column early on at the bottom
-shorter hydrocarbons have low boiling points, condense and drain out later on at the top
-crude oil mixture is separated in different fractions
what liquids are in the fractionating column?
bitumen
heavy fuel oil
diesel oil
kerosene
petrol
LPG
what is cracking?
splitting up long chain hydrocarbons
what hydrocarbon does cracking make?
alkenes
whats the test for alkenes?
bromine water
-when added to an alkene, the bromine reacts with the alkene to make a colourless compound
what type of method is cracking?
thermal decomposition
whats the process of cracking?
-heat long chain hydrocarbons to vaporise them
-vapour is passed over a hot powered aluminium oxide catalyst
-long chain molecules split apart on the surface = catalytic cracking
-vaporise them, mix them with steam and heat to a high temperature = steam cracking