How To Understand The Chemistry Of Oil

Transcription

1 Ca Making crude oil useful C: Carbon Chemistry Ca Making crude oil useful Name three fossil fuels? Crude oil, coal, natural gas What are non-renewable fuels? Ones which take a long time to make and are used up faster than they are formed What is meant by finite resources? Resources that are no longer being made or are being made extremely slowly. What is crude oil made of? A mixture of many different hydrocarbons What does fractional distillation do to crude Separates it into useful products called oil? fractions. Why can fractional distillation separate the substances in crude oil? The hydrocarbons in crude oil have different boiling points and so boil out at different What are the fractions obtained from crude oil? What is LPG? How does the temperature gradient in the fractionating column help to separate the hydrocarbons in crude oil? How does the mixture of hydrocarbon separate into fractions? Where do the low boiling fractions leave the column? Where do the high boiling fractions leave the column Name two environmental problems involved in the exploitation of crude oil. What further consequences could there be from the transportation of crude oil? temperatures. LPG, petrol, diesel, paraffin, heating oil, fuel oil and bitumen. In order of increasing boiling points. Liquefied petroleum gas, e.g. propane and butane. The column is cold at the top and hot at the bottom. The hot crude oil is put into the bottom of the column and the hydrocarbons separate. The vapours rise and cool. Hydrocarbons with similar boiling points condense in the same part of the tube and are piped off as a fraction. At the top of the column, they do not condense until the column is cool. At the bottom, they condense at high temperatures just after entering the column Oil slicks as a result of accidents Damage to wildlife and beaches. Damage to bird s feathers, preening oil can cause death. Detergents used to clean up spills can harm wildlife and the environment. Why are large hydrocarbons cracked to Smaller hydrocarbons are more useful as fuels, 0 make smaller ones? e.g. as petrol What are the conditions needed for You need a catalyst and a high temperature cracking? What happens to the large alkane They are converted into smaller alkane and molecules during cracking? alkene molecule. What are the alkene molecules used for? Alkene molecules are used to make polymers. Cb Using Carbon Fuels Cb Using Carbon Fuels What factors about fuels are used to choose the best fuel for a particular purpose? What makes petrol a good fuel for cars? Energy value, Availability, Storage, Cost, Toxicity, Pollution (e.g. greenhouse effect), Ease of use. Delivers enough energy to drive the engine, easily available at petrol stations because it burns quickly so cars need to refuel often, stored in a tank in the car, limited pollution

2 C: Carbon Chemistry due to catalytic converters, flows easily through small pipes with small pumps. What makes fuel oil a better fuel for ships than petrol? It delivers a huge amount of energy to drive the large engines, it is available at ports but burns very slowly so lasts a long time, It is very dense so it takes up little storage space on a ship, does call pollution, needs to be heated to get it to flow to the engines and to burn. What does the complete combustion of a Carbon dioxide, water and useful heat energy. hydrocarbon fuel produce? What does the complete combustion of a A plentiful supply of oxygen (air). To make sure hydrocarbon fuel need? that the carbon forms carbon dioxide. Construct a word equation to show the Methane + oxygen carbon dioxide + water complete combustion of methane in oxygen to form carbon dioxide and water. Describe an experiment to show that The products of a burning candle are drawn combustion of a hydrocarbon in a plentiful into a funnel and then over blue cobalt supply of air produces carbon dioxide and chloride paper and through limewater. water. How do you test for water and carbon Water: blue cobalt chloride goes pink in water dioxide? Carbon dioxide: limewater goes milky with CO Construct word equations to show the Propane + oxygen carbon dioxide + water complete combustion of propane. Why does incomplete combustion happen? Fuels are burnt without enough oxygen (air) What are the differences between the blue A blue Bunsen flame releases more energy as and yellow Bunsen flames? with the air-hole open it gets a plentiful supply of air. What does the incomplete combustion of a hydrocarbon fuel make? What is the problem with carbon monoxide? Construct a word equation to show the incomplete combustion of methane in oxygen to form carbon monoxide and water. Explain the advantages of complete combustion over incomplete combustion of hydrocarbon fuels. Construct word equations to show the incomplete combustion of propane. Cc Clean Air Cc Clean Air A yellow flame makes soot due to a lack of air. It makes carbon monoxide, carbon (soot), water and makes less energy than complete combustion. It s a poisonous gas! (stops blood carrying oxygen) limited Methane + oxygen carbon monoxide + water More energy is released and no carbon monoxide is produced. Propane + oxygen carbon monoxide + water Propane + oxygen carbon (soot) + water What is in air? Oxygen, nitrogen, carbon dioxide, water vapour. How do the amounts change on a daily They don t, cycles keep them stable. basis? How does photosynthesis affect the air? Removes carbon dioxide, adds oxygen

3 C: Carbon Chemistry How does respiration affect the air? Removes oxygen and adds carbon dioxide How does combustion affect the air? Removes oxygen and adds carbon dioxide What is the %composition of air % Nitrogen, % Oxygen, 0.0% carbon dioxide, about % Argon Describe a simple carbon cycle involving Photosynthesis removes CO and converts it photosynthesis, respiration and into sugar. Respiration takes sugar and combustion. converts it back into CO. Combustion makes Where did the original atmosphere come from? How did plants contribute to the make-up of today s level? How do the following pollute the air a. Carbon monoxide b. Nitrogen oxides c. Sulphur dioxide Where do these come from? a. Carbon monoxide b. Nitrogen oxides c. Sulphur dioxide CO from old sugar. The original atmosphere came from gases escaping from the interior of the Earth, volcanoes release large volumes of gas. Photosynthesis by plants increased the percentage of oxygen, %O, and reduced the %CO until they reached today s level. a. A poisonous gas b. Photochemical Smog and acid rain c. Acid rain, kills plants and aquatic life. a. Incomplete combustion in car engines b. Car engines c. Sulphur impurities in burning fuels What does a catalytic converter do? Turns CO into CO and NO into N Why should we control pollution in air? Small changes to the levels could have disastrous effects. Cd Making Polymers Cd Making Polymers What elements are hydrocarbons made from? How do you recognise a hydrocarbon from its molecular or displayed formula What atoms does a hydrocarbon contain? What are alkanes? Just hydrogen and carbon It just has carbon and hydrogen in it! Just hydrogen atoms and carbon atoms! (Doh!!) Alkanes are saturated hydrocarbons which contain only single covalent bonds. What is the general formula of an alkane? CnHn+ What are alkenes? Alkenes are unsaturated hydrocarbons which contain a double covalent bond(s) between carbon atoms. What is the general formula of an alkene? CnHn What is a double covalent bond made of? A single covalent bond has one shared pair of electrons; a double bond has two shared pairs. How can bromine water be used to test for unsaturation, the presence of a double Bromine water is orange when added but after shaking the bromine water is decolourised. bond? What is a monomer? A small molecule. What is a polymer? A large molecule made from many monomers. What is a polymerisation reaction? When large molecules, called polymers, are made by many small molecules, called

4 C: Carbon Chemistry monomers, joining together. What is addition polymerisation? Addition polymerisation is a process in which many alkene monomer molecules react together to give a polymer What conditions are needed for addition polymerisation? The older way needs high pressure and a catalyst. A newer way uses a catalyst and low temp solvent. What polymer does ethene make? Poly(ethene) What monomer is poly(propene) made Propene 0 from? The displayed formula for a polymer, poly(ethene) What is this? Ce Designer Polymers Ce Designer Polymers What is a more common name for polymers? What are the polymers used in clothes called? What is the man-made fibre nylon be used for? What properties of nylon make it suitable for this use? What properties does Gore-tex have? Why do active outdoor types have more use for gore-tex than nylon? (active = sweaty) What are the problems with plastics/polymers? How do you dispose of polymers/plastics? What types of new polymers are being developed to help with disposal? What environmental problems are associated with the use and disposal of polymers? What economic problems are associated with the use and disposal of polymers? plastics Man-made fibres Clothes Nylon is tough, lightweight, keeps water out and keeps UV light out but does not let water vapour through it which means that sweat condenses inside the nylon layer. Gore-Tex has all of the properties of nylon but is also breathable. The gore-tex lets sweat escape, whereas nylon kept it inside your clothes. Many polymers are non-biodegradable and so will not decay or decompose by bacterial action. Use of land-fill sites, burning of waste polymers, recycling. Polymers that dissolve, biodegradable polymers. They do not biodegrade but they do break up into tiny pieces which are eaten by birds and fish. They are made from oil; oil is running out, this will make new polymers more expensive. How long before land-fill sites become polymer mines. Cf Cooking and food additives Cf Cooking and food additives Explain why cooking food is a chemical A new substance is made and the process change cannot be reversed. Name two foods rich in protein. Protein molecules are found in eggs and meat

5 C: Carbon Chemistry What happens when protein is cooked? Protein molecules change shape when cooked What is this called? This is called denaturing What do these food additives do? Relate types of food additive to their function: i. Antioxidants. i. stop foods from reacting with oxygen ii. Food colours. ii. give processed food an improved colour iii. Flavour enhancers. iii. improve the flavour of a food iv. Emulsifiers. iv. help oil and water to mix and not separate. Describe emulsifiers. They are molecules that have a water loving hydrophilic) part and an oil or fat loving (hydrophobic) part. Why do cooks use baking powder? It makes cakes rise when it is cooked What is the chemical test for carbon dioxide The gas is bubbled through limewater. If it is gas? carbon dioxide the limewater goes cloudy. What is the active chemical in baking Sodium hydrogencarbonate, NaHCO powder? Recall the word equation for the sodium sodium + carbon + water decomposition of baking powder hydrogencarbonate carbonate dioxide Cg Smells Cg Smells Where do cosmetics come from? Cosmetics can be synthetic or natural. What are esters? Esters are perfumes that are made synthetically. How do you make an ester? Alcohols react with organic acids to make an ester and water Describe how to carry out a simple experiment to make an ester. Mix an alcohol with an organic acid with a catalyst such as sulphuric acid. Heat the Explain the physical properties of perfumes: a) evaporates easily b) non-toxic c) does not react with water d) does not irritate the skin e) insoluble in water. mixture. A perfume needs these properties so that: a) the perfume particles can easily reach the nose b) so it does not poison you c) otherwise the perfume would react with sweat d) otherwise the perfume couldn t be put on the skin e) so it cannot be washed off easily. What does nail-varnish remover do? It dissolves nail varnish colours. What do the terms solvent, solute, solution, soluble and insoluble mean? A solvent is a liquid that dissolves solutes to make a liquid called a solution. Solutes have to be soluble to dissolve. Things that don t dissolve are insoluble How would you describe a solution? A mixture of solvent and solute that does not separate out. What smelly chemicals can be used as Esters can be used as solvents. solvents? Why shouldn t you test cosmetics on The testing of cosmetics on animals is banned

6 C: Carbon Chemistry animals here in Britain? Explain why new cosmetic products need to be thoroughly tested before they are permitted to be used. in the EU. So that we know that it is non-toxic, that it does not react with water and that it does not irritate the skin. Ch Paints and Pigments Ch Paints and Pigments What is a pigment? The coloured substance, pigment in paint What else is in paint? A solvent and a binding medium. What does the solvent do? The solvent dissolves the pigment and/or the binding medium and makes the paint thin enough to spread. What does the binding medium do? This helps the paint to stick to walls. What special type of mixture is paint? A colloid, where the pigment particles are mixed and dispersed with particles of a liquid but are not dissolved What are paints used for? Decoration, protecting and sealing surfaces. How does paint dry? Watch it and see! The solvent evaporates. What is emulsion paint? A water based paint, i.e. the solvent is water. What is an oil paint? Oil paints have their pigment dispersed in oil and then the oil is dissolved in petrol. What is a thermochromic pigment? One that changes colour with temperature. Give two uses of thermochromic pigments? Cups that change colour, baby spoons, kettles. What is a phosphorescent pigment? When charged they glow in the dark How do phosphorescent pigments work? They absorb and store light energy and then after a period of time they release it.