AQA GCSE CHEMISTRY REVISION- C1.4 CRUDE OIL AND
FUELS QUESTIONS WITH CORRECT ANSWERS 2026-2027
Hydrocarbon - CORRECT ANSWER -A compound containing only hydrogen and carbon
Alkane - CORRECT ANSWER -ABsaturated hydrocarbon.
Saturated Hydrocarbon - CORRECT ANSWER -There is a single carbon-
carbon bond and no more hydrogen atoms can be added.
Where did crude oil come from? - CORRECT ANSWER -
Animals and plants sink to the bottom of the sea when they die, but do not decay as their is no oxygen f
or the bacteria to feed on. They are kept under high pressure and high temperatures so become crude o
il. This process takes millions of years.
Explain Fractional Distillation - CORRECT ANSWER -
Hot crude oil vapour is pumped into the bottom (the hottest part) of the fractionating column. As crude
oil is a mixture of hydrocarbons, as the vapour rises, and the temperature decreases different hydrocarb
ons with high-low boiling points condense and are pumped out of the column.
Properties of Hydrocarbons - CORRECT ANSWER -Long chain have:
high boiling points
low flammability
high viscoity
low volatillity
a smoky flame
Short chain have:
low boiling points
high flammability
low viscosity
high volatillity
, Less smoky (cleaner) flames
What does the boiling point of a hydrocarbon depend on? - CORRECT ANSWER -
The size of it's molecules
What is crude oil? - CORRECT ANSWER -A mixture of many different compounds, mainly hydrocarbons
What does a fuel react with in order to combust fully? - CORRECT ANSWER -Plenty of air, oxygen
What are the products of complete combustion? - CORRECT ANSWER -
Carbon dioxide and water (vapour)
Name five alkanes - CORRECT ANSWER -
Methane, Ethane, Propane, Butane, Pentane, Hexane, Heptane, Octane, Nonane, Decane
What does oxidised mean? - CORRECT ANSWER -
Oxidised is when oxygen is adding in a chemical reaction and oxides are formed
Why is sulphur dioxide a product of burning fuels? - CORRECT ANSWER -
The fuel contains sulphur impurities, which react with the oxygen to form sulphur dioxide
What problems does sulphur dioxide cause? - CORRECT ANSWER -
Sulphur dioxide is an acid and dissolves in water droplets in the air to from acid rain, which is harmful to
plants and animals.
How is carbon monoxide formed, and what problems does it cause? - CORRECT ANSWER -
Carbon monoxide is formed when there is not enough air for the fuel to burn with. This is called incomp
lete combustion. The problems of this is that Carbon monoxide is toxic, when the red blood cells pick it
up. This is bad becasue they carry the carbon monoxide around your body rather than the oxygen
What is the problem of diesel engines burningBbig hyrdocarbon molecules? - CORRECT ANSWER -
When the molecules react in the engine, they don't always burn fully. Particulates (solid particles contai
ng carbon and unburnt hyrocarbons) are produced, especially if the fuel is diesel.
FUELS QUESTIONS WITH CORRECT ANSWERS 2026-2027
Hydrocarbon - CORRECT ANSWER -A compound containing only hydrogen and carbon
Alkane - CORRECT ANSWER -ABsaturated hydrocarbon.
Saturated Hydrocarbon - CORRECT ANSWER -There is a single carbon-
carbon bond and no more hydrogen atoms can be added.
Where did crude oil come from? - CORRECT ANSWER -
Animals and plants sink to the bottom of the sea when they die, but do not decay as their is no oxygen f
or the bacteria to feed on. They are kept under high pressure and high temperatures so become crude o
il. This process takes millions of years.
Explain Fractional Distillation - CORRECT ANSWER -
Hot crude oil vapour is pumped into the bottom (the hottest part) of the fractionating column. As crude
oil is a mixture of hydrocarbons, as the vapour rises, and the temperature decreases different hydrocarb
ons with high-low boiling points condense and are pumped out of the column.
Properties of Hydrocarbons - CORRECT ANSWER -Long chain have:
high boiling points
low flammability
high viscoity
low volatillity
a smoky flame
Short chain have:
low boiling points
high flammability
low viscosity
high volatillity
, Less smoky (cleaner) flames
What does the boiling point of a hydrocarbon depend on? - CORRECT ANSWER -
The size of it's molecules
What is crude oil? - CORRECT ANSWER -A mixture of many different compounds, mainly hydrocarbons
What does a fuel react with in order to combust fully? - CORRECT ANSWER -Plenty of air, oxygen
What are the products of complete combustion? - CORRECT ANSWER -
Carbon dioxide and water (vapour)
Name five alkanes - CORRECT ANSWER -
Methane, Ethane, Propane, Butane, Pentane, Hexane, Heptane, Octane, Nonane, Decane
What does oxidised mean? - CORRECT ANSWER -
Oxidised is when oxygen is adding in a chemical reaction and oxides are formed
Why is sulphur dioxide a product of burning fuels? - CORRECT ANSWER -
The fuel contains sulphur impurities, which react with the oxygen to form sulphur dioxide
What problems does sulphur dioxide cause? - CORRECT ANSWER -
Sulphur dioxide is an acid and dissolves in water droplets in the air to from acid rain, which is harmful to
plants and animals.
How is carbon monoxide formed, and what problems does it cause? - CORRECT ANSWER -
Carbon monoxide is formed when there is not enough air for the fuel to burn with. This is called incomp
lete combustion. The problems of this is that Carbon monoxide is toxic, when the red blood cells pick it
up. This is bad becasue they carry the carbon monoxide around your body rather than the oxygen
What is the problem of diesel engines burningBbig hyrdocarbon molecules? - CORRECT ANSWER -
When the molecules react in the engine, they don't always burn fully. Particulates (solid particles contai
ng carbon and unburnt hyrocarbons) are produced, especially if the fuel is diesel.
