Combustion

• Combustion is when a fuel burns. The energy stored in the fuel is transferred to the surrondings.
• A hydrocarbon is made only of carbon and hydrogen. Many fuels are mainly hydrocarbons.
• Hydrocarbon combustion: hydrocarbon + oxygen = water + carbon dioxide.
• There are 3 things that are needed for something to be burnt. Oxygen, fuel and heat
• Burning is known as combustion.
• Complete combustion is when all the hydrogen in the fuel is burned and all the oxygen in the air is used up.
• Complete combustion: fuel + oxygen = carbon dioxide + water.
• Incomplete combustion: Fuel + oxygen = carbon monoxide + soot + water.
• Combustion is also an oxidation reaction because the substances react with oxygen.
• The mass of the reactants is always the same as the mass of the products.
• Metals can appear to gain mass when heated in air.
• In appliances that use carbon compounds as fuels and there is insufficient oxygen, carbon monoxide is formed.
• Carbon monoxide attaches to the hemoglobin in the blood and prevents it from carrying oxygen around the body.
• Exothermic reactions release energy to their surroundings, which we can feel as heat.
• Endothermic reactions absorb heat and cools the surroundings.
• Fire extinguishers work by cooling a fire or by stopping oxygen getting to the fuel.
• What are the problems with burning fuels

  Can cause acid rain and global warming.
• Acid rain is a type of precipitation that forms when compounds like sulfur dioxide and nitrogen oxides are released into the air and react with water, oxygen, and other chemicals.
• Sulphur dioxide and nitrogen oxide is let out into the atmosphere due to burning fuels.
• One way to prevent this is adding a catalytic converter to break

  down harmful gases. Reduce used of fossil fuels.
• Acid rain effects rivers and changes the pH in soils.
• The typical pH of Acid rain is 4. Which is very acidic.
• Combustion is a reaction in which a substance combines with oxygen and burns.
• A fuel is a substance that contains stored energy that can be released during burning.
• Oxygen is required for combustion
• Methane + oxygen = carbon dioxide + water
• Rusting is Iron + oxygen= Iron oxides
• Law of Conservation of Mass is the idea that mass is not lost or gained during a chemical reaction. The mass of all the reactants is equal to the mass of all the products.
• A pollutant is something that pollutes/harms the environment.
• What is acid rain?

  Rainwater that is acidic due to air pollution.
• Acid rain is caused by a chemical reaction that begins when compounds such as sulphur dioxide and oxides of nitrogen are released into the air. 
• Catalytic converters break down harmful gases and turn them into less harmful emmissions.