S2 Chemistry Materials from the Earth Fuels and combustion S2 Chemistry Materials from the Earth

Key Questions What is a fuel? How many examples of fuels can you name? What do all fuels have in common? What makes one fuel better than another?

Learning outcomes Success criteria Understand what fuels are. You can define the term “fuel”. You can state four examples of substances which are fuels. Know what is meant by “combustion”. You can define the term “combustion”. Know what is meant by an “exothermic reaction”. You can define the term “exothermic”. Know the percentage composition of air. You can name the two gases which make up most of air, including their percentage. You can name two other gases which are found in air, including a rough percentage.

Fuels and combustion A fuel is “a substance which is burned to release energy”. “Combustion” is another word for “burning”. Burning requires oxygen (O2). Burning is an “exothermic” reaction because it releases heat energy.

Challenge You have: Add water to the tub so that it is about ¼ full. A candle A plastic tub A match A match box A glass jar Add water to the tub so that it is about ¼ full. The challenge is to get the water from the tub into the glass jar without pouring it from the tub Once there is water in the tub, it is not allowed to move.

Air What is the percentage composition of air?

Learning outcomes Success criteria Understand what fuels are. You can define the term “fuel”. You can state four examples of substances which are fuels. Know what is meant by “combustion”. You can define the term “combustion”. Know what is meant by an “exothermic reaction”. You can define the term “exothermic”. Know the percentage composition of air. You can name the two gases which make up most of air, including their percentage. You can name two other gases which are found in air, including a rough percentage.

S2 Chemistry Materials from the Earth Types of combustion S2 Chemistry Materials from the Earth

Learning outcomes Success criteria Understand the difference between complete and incomplete combustion. You can describe examples of situations where complete and/or incomplete combustion will take place. You can write word equations for the complete and incomplete combustion of a hydrocarbon.

Types of combustion Look at a Bunsen burner and the different types of flame. There are 2 types of combustion complete and incomplete

Incomplete combustion Hydrocarbon + oxygen carbon dioxide + water Incomplete combustion Hydrocarbon oxygen carbon monoxide water + carbon

Learning outcomes Success criteria Understand the difference between complete and incomplete combustion. You can describe examples of situations where complete and/or incomplete combustion will take place. You can write word equations for the complete and incomplete combustion of a hydrocarbon.

Products of combustion S2 Chemistry Materials from the Earth

Learning outcomes Success criteria Know how to predict what products will be produced when a substance is burned. Given the names of elements in a fuel, you can state what products will be produced. You can name the products produced given the name of the elements present in a fuel.

Testing for the products of combustion Cobalt chloride paper Lime water

What evidence is there for complete combustion? What evidence is there for incomplete combustion? What THREE products does this experiment detect? What is an acceptable conclusion from this experiment? Carbon dioxide Carbon Carbon dioxide, water and carbon The candle contains carbon and hydrogen

Burning fuels When a substance burns ALL of the different types of atom in it react with oxygen Atom in fuel Products Carbon Carbon dioxide, carbon monoxide Hydrogen Hydrogen oxide (water) Sulphur Sulphur dioxide

Equations Write word and chemical equations for the following substances burning (complete combustion): Methane (CH4) Glucose (C6H12O6) Hydrogen (H2) Ethanol (C2H5OH) Carbon *Coal (contains carbon, hydrogen and sulphur) – no need for a chemical equation here

Learning outcomes Success criteria Know how to predict what products will be produced when a substance is burned. Given the names of elements in a fuel, you can state what products will be produced. You can name the products produced given the name of the elements present in a fuel.

S2 Chemistry Materials from the Earth Oxides of carbon S2 Chemistry Materials from the Earth

Learning outcomes Success criteria Know characteristic properties of carbon dioxide and carbon monoxide. You can describe the properties of carbon dioxide and carbon monoxide, including: State at room temperature Flammability You can state why high concentrations of carbon monoxide are dangerous. You can state the test for carbon dioxide gas, naming the chemical you would use and the result.

Carbon Dioxide vs Monoxide Chemical Formula Chemical Test Other information Carbon dioxide CO2 Lime water turns from colourless to cloudy We breath it out; it makes drinks fizzy; it dissolves in water producing a weak acid; it is associated with “global warming” Carbon monoxide CO No test Poisonous gas, does not dissolve

Learning outcomes Success criteria Know characteristic properties of carbon dioxide and carbon monoxide. You can describe the properties of carbon dioxide and carbon monoxide, including: State at room temperature Flammability You can state why high concentrations of carbon monoxide are dangerous. You can state the test for carbon dioxide gas, naming the chemical you would use and the result.

S2 Chemistry Materials from the Earth Fossil Fuels S2 Chemistry Materials from the Earth

Learning outcomes Success criteria Know what is meant by a fossil fuel. You can name the three main fossil fuels. Know how fossil fuels are formed. You can describe the formation of coal, oil and natural gas. Understand why fossil fuels are a finite resource. You can state what is meant by a finite resource. You can explain why fossil fuels are likely to run out.

Which of these are fossil fuels?

Which fuels are fossil fuels? The three main fossil fuels are: Coal Crude Oil Natural Gas

Coal Formation of Coal: dead remains of trees covered in layers of mud high temperature and pressure over millions of years

Crude Oil Formation of Crude Oil: dead remains of marine life covered in layers of sand high temperature and pressure over millions of years

Natural Gas Formation of Natural Gas: formed at the same time as oil layer trapped on top of oil

Find out… When are each of the three fossil fuels predicted to run out?

Learning outcomes Success criteria Know what is meant by a fossil fuel. You can name the three main fossil fuels. Know how fossil fuels are formed. You can describe the formation of coal, oil and natural gas. Understand why fossil fuels are a finite resource. You can state what is meant by a finite resource. You can explain why fossil fuels are likely to run out.