Day 4 AQA revision - organic chemistry

What is the name of the alkane with two carbon atoms?

• Ethane

• Methane

• Butane

• Propane

What chemicals are found in crude oil?

• Methane only

• A mixture of compounds, which are mostly hydrocarbons

• A mixture of elements

• Carbon only

What is the definition of a hydrocarbon?

• A compound made of hydrogen and carbon only

• A compound that includes hydrogen or carbon

• A mixture that includes hydrogen and carbon

• A mixture of hydrogen and carbon only

What is the first stage in the fractional distillation of crude oil?

• Heating, to vaporise the hydrocarbons

• Heating, to make it a hot liquid

• Cooling it

• Separating the fractions

What happens to the viscosity of hydrocarbons as the length of the molecule increases?

• Longer hydrocarbons are more viscous

• All hydrocarbons have the same viscosity

• Hydrocarbons aren’t viscous

• Shorter hydrocarbons are more viscous

What compounds are produced in the complete combustion of hydrocarbons?

• Carbon dioxide and water

• Carbon monoxide and water

• Carbon dioxide and nitrogen

• Water and nitrogen

The alkanes are a homologous series.

What is the general formula of the alkanes?

• n carbon atoms, 2n hydrogen atoms

• 2n carbon atoms, n hydrogen atoms

• n carbon atoms, n+2 hydrogen atoms

• n carbon atoms, 2n+2 hydrogen atoms

What property allows us to separate hydrocarbons during fractional distillation?

• Different hydrocarbons have different boiling points

• Different hydrocarbons have different melting points

• Different hydrocarbons are different colours

• Some hydrocarbons have a positive charge and others have a negative charge

Which is the best description of fractional distillation?

• Breaking down longer hydrocarbon chains into smaller ones that are more useful

• Separating the hydrocarbons in crude oil into fractions, with each fraction containing molecules with a similar number of carbon atoms

• Pumping crude oil out from under the sea

• Ensuring resources are used to meet the needs of current generations without compromising the needs of future generations

Crude oil is finite because we use it before more can be formed.

How was crude oil formed?

• From the remains of an ancient biomass, consisting mainly of plankton, that was buried in mud

• Mostly from the remains of dinosaur bones

• By fractional distillation

• By cracking