Presentation on theme: "Formation, Composition, Purification and Properties"— Presentation transcript:
1 Formation, Composition, Purification and Properties Crude OilFormation, Composition, Purification and Properties
2 Crude oil is found in the Earth’s crust Formation of OilCrude oil is found in the Earth’s crustIt was formed from the remains of sea creatures that lived millions of years agoIt is a fossil fuelFormation of Oil
3 Formation of oil and gas 1) Layers of dead sea _____ settle on the seabed.2) Layers of __________ rock build up on top.3) The heat and ________ from these rocks, along with the absence of ______, mean that oil and gas are formed over ______ of years.Words – sedimentary, millions, oxygen, creatures, pressure
6 Crude oil contains a mixture of hydrocarbons Hydrocarbons have different lengths and therefore different boiling pointsThey can be separated by fractional distillationEach fraction is put to a different use depending on the properties of the hydrocarbonCrude Oil
9 Uses of hydrocarbonsMost of the hydrocarbons present in crude oil can be used as fuels because they burn easily and give out a lot of heat energy.As the chain length increases they become less flammable and so purification is aimed to make simple mixtures containing similar molecules with similar behaviour.Crude Oil
11 Fractional distillation Crude oil can be separated by fractional distillation. The oil is evaporated and the hydrocarbon chains of different lengths condense at different temperatures:Fractions with low boiling points condense at the topFractions with high boiling points condense at the bottom
12 The longer the carbon chain the; Higher the boiling point HydrocarbonsA hydrocarbon is a molecule which contains hydrogen and carbon atoms onlyThe longer the carbon chain the;Higher the boiling pointLess volatile it isMore viscous it isLess flammable it isHydrocarbons
14 Which is a correct statement about crude oil? A mixture of carbohydrates.Formed by the decay of dead sea creatures.Consist of a mixture of very large molecules.Is purified in an oil rig.
15 Which is a correct statement about fractional distillation?Oil is separated into fractions with the same size molecule.Oil is separated into fractions with the same density.Oil is separated into fractions with similar size molecules.Oil is separated into alkanes and alkenes.
16 Which is a correct order for these fractions working down from the top of the column? Fuel gas, kerosine, petrol, diesel, bitumen.Fuel gas, diesel, kerosine, petrol, bitumen.Fuel gas, petrol, diesel, kerosine, bitumen.Fuel gas, petrol, kerosine, diesel, bitumen.
17 Which of these is a true statement about the changes that occur as hydrocarbon molecules get larger? Boiling point decreases.Viscosity increases.Flammability increases.Transparency increases.
18 Problems caused by burning hydrocarbons When a hydrocarbon burns carbon dioxide and water are made.E.g. CH4 + 3O2 → CO2+ 2H2OCarbon dioxide adds to the greenhouse effect.All fuels also contain sulphur impurities from the original sea creatures. When the sulphur burns in an engine sulphur dioxide is made.Sulphur dioxide adds to acid rainHydrocarbons