What is crude oil?
Crude oil is a mixture of many different compounds which boil at different temperatures, but mainly hydrocarbons.
What are hydrocarbons?
Hydrocarbons are molecules which only contain hydrogen and carbon.
What are alkenes?
Alkenes are unsaturated hydrocarbons.
What are alkanes?
Alkanes are saturated hydrocarbons. They contain as many hydrogen atoms as possible in their molecules.
Describe some properties of short hydrocarbon molecules.
-Are runny (less viscous).
-Have low boiling points.
How was crude oil formed?
Crude oil is found trapped in sedimentary rocks in the Earth's crust.
Fossil fuels are formed over millions of years from the fossilised remains of dead plants and animals.
What is the general formula for alkanes?
Define fractional distillation.
Fractional distillation separates a mixture into separate parts called fractions.
Describe the steps involved in the fractional distillation of crude oil (3 marks).
Crude oil is heated and turned to vapour (1). The tall column is hot at the bottom and gets cooler going up the column. The hydrocarbon vapours condense (1) at different temperatures (1). The shortest hydrocarbons collect at the top of the column.
What is produced in complete combustion?
Fuel + oxygen➡️ water + CO2.
The fuel is oxidised when there is plenty of air.
What is produced in incomplete combustion?
Fuel + Oxygen➡️ Water + CO2 + Carbon + Carbon Monoxide.
In a limited supply of air incomplete combustion may produce carbon monoxide.
How can sulfur dioxide be produced during combustion?
Any sulfur compounds in the fuel burn to produce sulfur dioxide.
How can nitrogen oxides be produced during combustion?
Oxides of nitrogen can be formed when fuels burn at high temperatures.
What environmental problem is caused by sulfur dioxide and nitrogen oxides?
Both cause acid rain.
Name the product of incomplete combustion that scientists believe causes global dimming.
Particulates produced in incomplete combustion cause global dimming.
Why might they remove sulfur from fuels before they are burned?
To reduce the amount of sulfur dioxide given off.
What do many scientists believe is the cause of global warming?
CO2 from burning fuels,
How can you reduce the amount of carbon monoxide (CO) produced in incomplete combustion?
Use a catalytic converter.
What are biofuels?
Biofuels and fuels made from plant or animal products. They are renewable.
How is biodiesel made?
Biodiesel can be made from vegetable oils extracted from plants.
An alkali and catalyst is added to the veg oil to make biodiesel.
How is ethanol made?
Ethanol can be made from starch or sugar producing plants.
The starch is made into sugar and yeast is added to make ethanol.
Suggest the advantages and disadvantages of extracting petroleum products from oil sands in Canada (6 marks).
A- Help keep up with increasing demands for petroleum products.
A- Could improve Canada's economy.
A- Provide employment for a lot of people.
A- Trees could be used for fuel.
D- Destruction of habitats/environments.
D- Crude oil is non renewable.
D- Energy needed for cracking/distillation.
D- There are fewer trees to absorb CO2.
Describe the conditions used for the two reactions that produce ethanol from octane (4 marks).
Octane vapours (1) are passed over catalyst to produce ethene (1). Steam is added (1) in the presence of a catalyst (1).
The production of low-carbon steel uses oxygen but the production of titanium uses argon. Why?
Oxygen is needed in steel production to oxidise carbon (1.) If oxygen was used then the titanium would react (1). Argon is used because it's a noble gas and is unreactive (1).