Air and Water1. The air consist of 78% of nitrogen; 21% of oxygen and the remaining 1% are others gases ( CO2; water vapour and noble gases)2. Oxygen is important to us as we need it for the process called respiration.3. Glucose + oxygen carbon dioxide + water + energy4. The energy from respiration keeps us warm and allow us to move as well as contributing to different reaction in our bodies.Measuring the percentage of oxygen in air

1. Heat the tube containing copper using Bunsen burner. Then push in plunge A and force the air to plunge B and from B to A. Repeat few times. Oxygen will react with copper, turning it black.2. Stop heating after about 3 minutes, and allow it to cool. Then push the air into one syringe and measure its volume.3. Repeat step 1 and 2 until the volume of the gas remain steady.Separation of air1. Air can be separated using fractional distillation but first air is cooled to liquid before proceeding.

1. Air is pumped into the plant, and filtered to remove the particles.2. Next, water vapour, carbon dioxide and pollutant are removed.3. Then the air is compressed and is cooled down again by recycling cold air.4. The cold, compressed air is passed through a jet, into a larger space allowing the air to expand rapidly which makes it very cold.Note: Step 3 & 4 are repeated several times and each time the air get cooler.5. The liquid air is pumped into the fractionating column. It is slowly warmed up and the gases boil off one by one.The main air pollutantPollutantSourcesHarm

Carbon monoxideWhen carbon compound in fossil fuels burnt in absent/too little of air.Poisonous as it combined with haemoglobin in blood and prevents it from carrying oxygen around the body.

Sulphur dioxideWhen Sulphur compound in fossil fuels burnt. Power station are the main source.Irritates the eyes and throat and causes respiration problem. Causes acid rain that corrodes building walls, sculpture.

Nitrogen oxidesWhen nitrogen and oxygen react together.Cause respiratory problem and acid rain

Lead compoundsCombustion of tetra-etyl lead will produce particles of other lead compoundDamage childrens brains and it also damage kidneys and nervous system in adults

Ways to reduce air pollution1. Through flue gas desulfurization2. Banning of lead in petrol3. Using catalytic converters in exhaust.

Catalytic converter1. Harmful gases are produced when petrol is burned.2. Catalytic converter absorbed these harmful gases and form other gases that are not harmful.3. The catalyst are usually made of transition element such as platimum, palladium, and rhodiums which are coated onto a ceramic honeycomb (increase surface area). 4. The converter usually have two compartment A and B:A: harmful component are reduced. Nitrogen and oxygen is flowed to B. 2NO(g) N2(g) + O2(g) B: harmful compounds are oxidized, using the oxygen from A. 2CO(g) + O2(g) 2CO2(g)The harmless products then flow out the exhaust pipe.Rusting1. Rusting is the corrosion of iron and steel.2. Testing of rusting:a. Test tube with dry air (calcium carbonate to dry the air) b. Test tube with boiled waterc. Test tube with air and waterd. As a result, the nail in C has rust on it. Rusting required water and air.e. 4Fe(s) + 3O2(g) + 4H2O(l) 2Fe2O3.2H2O(s) 3. Way to prevent rusting:a. Cover the iron: Paint Grease Galvanising b. Sacrificial protectionWater1. Uses of water:PlacesUses

HomeDrinking, cooking, washing

FarmsDrinking and water crops

IndustrySolvent, Washing, Cooling

Power stationMake steam which drive the turbine

2. Underground water are known as groundwater and the rocks that trap or hold the underground water is known as aquifer.3. Water treatment:i. The water is pumped in and a screen is used to trap big particles.ii. A coagulant is added to make the suspended small particles stick together. (iron(III) sulfate)iii. Air is blown through the water in floatation tanks to make the coagulated particles to float and are skimmed off.iv. The water is then passed through a bed of fine sand to filter it.v. The water may go through further filter such as more sand or charcoal to remove bad taste and odour.vi. Chlorine is added to kill bacteria and microbesvii. Fluoride is added to prevent tooth decay.viii. Lastly, water is pumped to the storage reservoir ready to pump to homes.