Keywords : Carbon monoxide, unburnt hydrocarbons, particles, sulfur compounds, sulfur dioxide

1. Burning Fuels Prior Learning: Know what fractional distillation is & how it separates Keywords: Carbon monoxide, unburnt hydrocarbons, particles, sulfur compounds, sulfur dioxide

2. Learning Objectives: Identify and explain • The combustion products formed from fuels. • That in a combustion reaction, the amount of oxygen available to react affects the products produced. • The pollutants produced when we burn fuels. I will be successful in this lesson if I can: • Write word equations for the complete combustion of hydrocarbons (Lvl C). • Describe differences between incomplete and complete combustion (Lvl C). • List pollutants formed when we burn fuels (Lvl C). • Complete balanced symbol equations for the complete and incomplete combustion of simple alkanes (Lvl A). • Explain how nitrogen oxides, sulfur dioxide and particulates are produced during the combustion process (Lvl A).

3. Hydrocarbons contain only hydrogen & carbon 7. Carbon dioxide can be tested with a glowing splint TRUE FALSE 2. Fuels can only be hydrocarbons 8. Oxygen can be tested with limewater 3. A fuel is burned to release energy 9. Water can be tested with blue cobalt chloride paper 10. Sulfur dioxide can be made by burning fossil fuels 4. Fuel is stored light energy 5. Combustion is a reduction reaction 6. When hydrocarbons burn in plenty of oxygen, carbon dioxide & water is made

4. Combustion is the scientific word for burning and is a type of chemical reaction. I know… I know… BUT STILL You should have learnt this in Yr 7 Combustion is the reaction when a substance burns and reacts with oxygen to produce heat and light energy.

5. When a substance burns, it is said to combust. Combustion is a rapid reaction between a substance and oxygen that releases heat and light energy. A fuel is a substance that reacts with oxygen (combusts) to release useful energy. Many fractions obtained from crude oil are used as fuels because they contain hydrocarbons that burn easily and release a large amount of useful energy.

7. methane oxygen carbon dioxide water The natural gas, methane, is often burnt for cooking. Methane is made up of carbon and hydrogen. What is the chemical equation? • What gas does methane react with when it burns? oxygen • What substance will the carbon in methane change into when it burns in oxygen? carbon dioxide • What substance will the hydrogen in methane change into when it burns in oxygen? water • What is the word equation for the combustion of methane? CH4 2O2 CO2 2H2O

8. Combustion demonstration How can we demonstrate combustion & the products of combustion with the provided equipment?

10. carbon dioxide + + hydrocarbon oxygen  water Plenty of air is needed to provide enough oxygen for a hydrocarbon fuel to burn completely. The blue flame of a gas hob or a Bunsen burner is an example of complete combustion of a hydrocarbon (in this case, natural gas). What are the products of thecomplete combustion of a hydrocarbon?

11. If there is a shortage of air (oxygen), incomplete combustion of hydrocarbons takes place. Instead of producing just carbon dioxide and water, incomplete combustion also produces carbon monoxide and/or carbon (soot). These form tiny particle in the air (particulates). It also releases less energy than complete combustion. Carbon monoxide is a poisonous gas because it reduces the ability of blood to carry oxygen. Most fuels contain sulfur compounds. When the fuel burns, these sulfur compounds produce sulfur dioxide.

12. Complete or Incomplete combustion? With the yellow bunsen flame the oxygen flow is restricted & incomplete combustion occurs. Therefore, a lower temperature is achieved & soot is produced With the blue bunsen flame the oxygen flow is in excess & complete combustion occurs. Therefore, combustion is most efficient under these conditions, producing high temperatures & only carbon dioxide & water

13. Combustion of Propane • What type of chemical is propane?2. How many carbons in its carbon chain? 3. What happens when there is plenty of oxygen? 4. What happens when there is a shortage of oxygen? DEMONSTRATION: ‘Burning Propane’ C1a 3.3

14. carbon dioxide + + propane oxygen  water + + C3H8 5O2  3CO2 4H20 Propane is a hydrocarbon used in camping gas. What is the equation for its combustion? How would the equations change if butane was used?

15. CH4 Wax CH4 Petrol 2O2 oxygen 8O2 water H2O Complete these word (symbol) equations 1. Carbon dioxide carbon dioxide 2. Oxygen Water carbon Carbon monoxide 3. CO2 2H2O 6 8 CO2 12 4. CO C 2 3

16. In pairs, write a summary sentence about as many of these words as you can…. You will be asked to read out your sentences & copy down the correct ones • Combustion • Nitrogen oxide • Sulfur dioxide • Particulates

18. Learning Objectives: Identify and explain • The combustion products formed from fuels. • That in a combustion reaction, the amount of oxygen available to react affects the products produced. • The pollutants produced when we burn fuels. I will be successful in this lesson if I can: • Write word equations for the complete combustion of hydrocarbons (Lvl C). • Describe differences between incomplete and complete combustion (Lvl C). • List pollutants formed when we burn fuels (Lvl C). • Complete balanced symbol equations for the complete and incomplete combustion of simple alkanes (Lvl A). • Explain how nitrogen oxides, sulfur dioxide and particulates are produced during the combustion process (Lvl A).