Why is crude oil described as a finite resource?

It takes millions of years to form and is being used far faster than it is replaced, so the supply will eventually run out.

Give three ways in which modern life depends on hydrocarbons.

They fuel almost all transport, they heat homes and generate electricity, and they are the raw material for plastics, medicines and other chemicals.

Explain why transport in particular depends on hydrocarbons.

Petrol, diesel and kerosene release a great deal of energy for their mass and are easy to store and transport, so they power almost all cars, lorries, ships and aircraft.

What is likely to happen to the cost of crude oil products as reserves fall?

Remaining oil becomes harder and more expensive to extract, so prices rise and alternatives become more attractive.

Give one argument that crude oil is too valuable to burn.

Once it is burned it is gone for good, and it is the only convenient source of the molecules used to make plastics, medicines and dyes.

Give a use of hydrocarbons that does not involve burning them.

They are used as lubricants, as road surfacing and as the starting materials for polymers.

OCR GCSE Combined Science Chemistry J250

Chemical Reactions

Topic overview Writing formulae of elements and compounds Balanced equations, and deducing formulae from ions State symbols in equations Conservation of mass, and changes of mass in open systems Exothermic and endothermic reactions, and reaction profiles Activation energy and why reactions need it Oxidation and reduction in terms of oxygen Acids, alkalis and neutralisation The ionic equation for neutralisation, and reactions of acids The pH scale, acidity and alkalinity Measuring pH with indicators and pH meters Products at the electrodes, and molten ionic compounds Electrolysis of aqueous solutions Inert and non-inert electrodes

Elements, Compounds and Mixtures

Topic overview Purity, and melting point data Relative formula mass and empirical formulae Formulations, and separating mixtures Paper and thin layer chromatography Interpreting chromatograms and Rf values Choosing a purification method Metals and non-metals in the Periodic Table Electron arrangement and position in the Periodic Table Ionic, covalent and metallic bonding compared Dot and cross diagrams, and the limits of models Reactions, electron arrangement and Mendeleev's table Carbon's four bonds, and the variety of organic compounds Diamond, graphite, fullerenes and graphene Bond strength, intermolecular forces and predicting state Bulk properties of ionic, molecular and giant structures

Global Challenges

Topic overview Extracting metals by reduction and by electrolysis Life cycle assessment Recycling, and the decisions behind it Fractional distillation of crude oil The fractions, and crude oil as a feedstock Dependence on hydrocarbons, and cracking The Earth's early atmosphere, and how oxygen developed The greenhouse effect, and evidence for climate change Effects of carbon dioxide and methane, and air pollutants Producing potable water

Monitoring and Controlling Chemical Reactions

Topic overview Measuring the rate of a reaction, and rate graphs Factors affecting rate, and collision theory Surface area and rate Catalysts and how they work Reversible reactions and dynamic equilibrium Activation energy, and enzymes as catalysts

Particles

Topic overview The particle model and changes of state How the atomic model changed, and the structure of the atom The size of atoms, and the subatomic particles Calculating protons, neutrons and electrons

Predicting and Identifying Reactions

Topic overview Groups 1, 7 and 0, and why they behave as they do Predicting reactivity from the Periodic Table Reactivity of metals with water and acids Tests for oxygen, hydrogen, carbon dioxide and chlorine

Global Challenges

Dependence on hydrocarbons, and cracking

3 things to know
Paper 4 (Chemistry)

Overview

Why crude oil is finite and how modern life and transport depend on hydrocarbons, rising costs, arguments against burning oil, uses that do not burn it, pollution concerns, why replacing hydrocarbon fuels is hard, what cracking is and why refineries do it, the conditions for catalytic and steam cracking, its products and equation, and the ethical case against burning oil so quickly.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

Suggest why replacing hydrocarbon fuels is difficult even though they are finite.

Key term

Why do oil refineries crack the longer fractions?

Key term

Describe the conditions used for catalytic cracking.

Questions from this subtopic

Each one with the model answer underneath.

1
Why is crude oil described as a finite resource?
Model answer
It takes millions of years to form and is being used far faster than it is replaced, so the supply will eventually run out.
2
Give three ways in which modern life depends on hydrocarbons.
Model answer
They fuel almost all transport, they heat homes and generate electricity, and they are the raw material for plastics, medicines and other chemicals.
3
Explain why transport in particular depends on hydrocarbons.
Model answer
Petrol, diesel and kerosene release a great deal of energy for their mass and are easy to store and transport, so they power almost all cars, lorries, ships and aircraft.
4
What is likely to happen to the cost of crude oil products as reserves fall?
Model answer
Remaining oil becomes harder and more expensive to extract, so prices rise and alternatives become more attractive.
5
Give one argument that crude oil is too valuable to burn.
Model answer
Once it is burned it is gone for good, and it is the only convenient source of the molecules used to make plastics, medicines and dyes.
6
Give a use of hydrocarbons that does not involve burning them.
Model answer
They are used as lubricants, as road surfacing and as the starting materials for polymers.

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Chemical Reactions

Elements, Compounds and Mixtures

Global Challenges

Monitoring and Controlling Chemical Reactions

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