As part of their work on crude oil, gcse chemistry students will look at thermal cracking. What is a polymer polymers are very large molecules sometimes called macromolecules. Cracking fuels edexcel gcse chemistry single science. Cracking is the most important process for the commercial production of gasoline and diesel fuel. Did you use a plastic bottle, a plastic bag, a blanket, a toy, a basketball, a toothbrush, a lunch box, a rope.
The reason for this is that cracking produces a new family of. Cracking and alkenes crude oil, hydrocarbons and alkanes. Doc browns gcseigcseo level ks4 sciencechemistry revision notes. Each polymer molecule is a long chain of mainly carbon atoms polymers are made from many smaller molecules, called monomers. What are some differences between cracking and polymerisation. A short videoaudio guide explaining the essentials of cracking and polymerization. Why do long hydrocarbons have higher boiling points. Cracking edexcel igcse chemistry notes save my exams. Condensation polymerization materials world modules. Thermal cracking and catalytic cracking are two major processes used in petroleum refineries in order to obtain useful products out of crude oil distillates. These monomers the starting materials are often alkenes the process chemical reaction that turns monomers into polymers. Cracking and alkenes gcse chemistry single science revision. Modern living is built on crude oil this hub explains how crude oil is changed into the things we use everyday, from petrol to plastic. Your students can be examready with this fantastic resource.
These long chain molecules can be made up from tens of thousands of monomers joined together. The rate of catalyst greatly depends upon the factors such as the presence of catalyst and temperature. Polymerisation and cracking gcse science marked by. A they are used to produce polymers are the starting material for other chemicals. The process of converting a monomer or a mixture of monomers into a polymer. Crude oil is made of long hydrocarbon chains which can be distilled or refined into various products such as diesel and petrol. Fractional distillation of crude oil produces useful fractions and notsouseful fractions. C1 alkenes, cracking and polymers flashcards in gcse. Gcse polymerisation revise reaction of monomer molecules. Difference between thermal cracking and catalytic cracking. This process is called polymerisation when alkenes join together to form a polymer with no other substance being produced in the reaction, the process is called addition polymerisation. This means that large hydrocarbon molecules break into. Cracking definition, in the distillation of petroleum or the like the process of breaking down certain hydrocarbons into simpler ones of lower boiling points by means of excess heat, distillation under pressure, etc. The process is known as catalytic cracking because it only happens in the presence of a catalyst substance which speeds up the reaction without being used up itself.
It is the principal industrial method for producing lighter alkenes olefins, including ethene or ethylene and propene or propylene figure 3. Revise and summarise the key information for unit 7. Butene, also known as butylene, is a series of alkenes with the general formula c 4 h 8. Gcse chemistry revision covering cracking and its products, hydrocarbons, catalyst, thermal decomposition, alkanes, single covalent bonds, alkenes, double covalent bonds, and cracking paraffin. Petrochemicals and polymers, petroleum, alternative fuels and energy sources, addition polymerisation, condensation polymerisation. You can see that hexane c6h14 is being cracked to form ethane c2h4 and butane c4h10. Cracking oil and cracking gcse chemistry single science. This website and its content is subject to our terms and conditions. Oil, useful products, environmental problems, introduction to organic chemistry. Petrol and other fuels are produced from it using fractional distillation. Cracking is used to convert long alkanes into shorter, more useful hydrocarbons. The structures of four organic compounds are shown. The mechanism of catalytic cracking of hydrocarbons is ionic. Polymerisation happens when monomers react to form long chain polymer molecules.
Condensation polymerisation involves a reaction between monomers with two different functional groups. Cracking hydrocarbons edexcel gcse chemistry revision notes. Petrol and other fuels are produced from it using fractional distillation and cracking. Catalytic cracking process was invented by eugene houdry in 1937. Making crude oil usefulfractional distillation and cracking. This is achieved by using high pressures and temperatures without a catalyst, or lower temperatures and pressures in the presence of a catalyst. One of the topics covered in gcse chemistry is polymerisation. What are the differences between cracking and polymerisation. The reactions that take place in a refinery includes distillation, cracking reactions, reforming reactions, polymerization, isomerization, etc. For example, ethene molecules can react together to form polyethene, a polymer.
You know that monomers that are joined by condensation polymerization have two functional groups. Ethene is probably the most economically useful product of cracking, as it is used in many different applications in society, as plastics polythenes. Catalytic cracking thermal cracking there are many types of catalysts, some common ones are zeolites and a mixture of silicon. There are two types of polymerization, addition polymerization, and condensation polymerization. Best igcse organic chemistry notes complete breakdown. They are colourless gases that are present in crude oil as a minor constituent in quantities that are too small for viable extraction. Paraffinic feedstocks are best for optimising ethylene yields, and the severity of cracking is specified by the rate of disappearance of a marker compound, usually npentane. In polymer chemistry, polymerization is a process of reacting monomer molecules. Cracking is the name given to breaking up large hydrocarbon molecules into smaller and more useful bits. Cracking and polymerisation video teaching resources.
Thermal cracking and catalytic cracking are such reactions that are used to break down large molecules into smaller compounds. But when some of the fractions of crude oil are cracked, a whole new world of chemistry opens up. Steam cracking is a petrochemical process in which saturated hydrocarbons are broken down into smaller, often unsaturated, hydrocarbons. A chemical change occurs when one substance is transformed into one or more new products via a chemical reaction. Cracking and polymerization video teaching resources.
Fractions containing large hydrocarbon molecules are heated to vaporise them. Gcse crude oil revise the thermal cracking reaction. Igcse organic chemistry notes february 18, 2018 january 31. Tes global ltd is registered in england company no 02017289 with its registered office. This type of polymerisation is called addition polymerisation. In a chemical change, the number and type of atoms remain constant, but their arrangement is altered. How does it work why is crude oil both important and useless. So heavy hydrocarbon molecules are broken up into lighter molecules. In industry they use silica silicon oxide or alumina aluminium oxide. The word butene may refer to any of the individual compounds, or to a mixture of them. Polymers are large molecules that are made up of many. They are formed when many small molecules join together. When these types of monomers react they join together, usually losing a small molecule such as water, and so the reactions are called condensation reactions.
Manufacture molecular structure uses problems and their solution. Designed for gcse revision, this high res animation is comprehensive in its coverage, and can also be used on a large screen as your main teaching resource for the topic. Revise what you learned in year 10 and year 11 in this exciting quiz. Cracking is defined as a process, wherein complex organic molecules namely long chain hydrocarbons or kerogens are broken down into smaller molecules namely light hydrocarbons. To familiarise you with it, weve created this interactive quiz. They are also the precursor in the production of many types of plastics and resins via polymerisation reactions. Polymerization, any process in which relatively small molecules, called monomers, combine chemically to produce a very large chainlike or network molecule, called a polymer. This summarises the key topics for the organic chemistry unit, including crude oil, the structure of alkanes, fractional distillation, properties of hydrocarbons, cracking, alkenes and polymerization. The end result is in smaller hydrocarbon molecules. The products of cracking in all cases are then returned to be fractionally distilled once again and separated according to need. Organic chemistry from the combined science aqa gcse chemistry specification. Cracking of hydrocarbons involves thermal decomposition. It is caused by the breaking of carboncarbon bonds.
You also know from part 6 that a carboxylic acid and an amine can form an amide linkage, jand a carboxylic acid and an. Polymerisation is the reaction of monomer molecules to form long chain polymer molecules. Its written by teachers especially to help year 10 and year 11 students revise. The main difference between thermal cracking and catalytic cracking is that thermal cracking uses heat energy for the breakdown of. Gcse chemistry revision science section covering cracking and its products, hydrocarbons, catalyst, thermal decomposition, alkanes, single and double covalent bonds, and cracking paraffin. Cracking in this case means breaking chemical bonds in molecules so they split apart. An example of alkene polymerization, in which each styrene monomers double bond reforms as a single bond plus a bond to another styrene monomer. Addition polymerisation is the name given to a chemical reaction in which unsaturated monomers are joined, forming a polymer. A monomer is a small reactive molecule that can be joined with other monomers to form long chains. Gcse science chemistry 91 crude oil and hydrocarbons duration. The bulk of the major monomer and intermediate, ethylene c 2 h 4, is still produced in the uk by steam cracking without the use of catalysts. Tough gcse topics broken down and explained by out team of expert teachers. Take this quiz and discover what you know about drawing diagrams of addition polymers. This is done by means of heat, pressure, and sometimes catalysts.
Thermal cracking was invented in 1930 by william meriam burton. Alkenes are reactive and so are useful for making many other substances including polymers polymers have very large molecules. The monomer molecules may be all alike, or they may represent two, three, or more different compounds. Home about inspector calls gcseigcse search take a break motivation you are here. Learn about the properties of polymers and how they can be used with bbc bitesize gcse chemistry. Alkenes can take part in reactions that alkanes cannot. Both techniques have advantages as well as drawbacks. Some are common sense but make sure to test yourself afterward as at least 10 marks in every test will go to definitions. Making polymers, plastics, uses, problems and recycling. Learn about and revise fuels with this bbc bitesize gcse chemistry.
Gcse chemistry definitions when learning definitions i find it easier to move around and say them to yourself. Cracking, in petroleum refining, the process by which heavy hydrocarbon molecules are broken up into lighter molecules by means of heat and usually pressure and sometimes catalysts. Polymerisation is the name given to the reaction that produces polymers. You can print out the corresponding worksheet or answer the. Addition polymers properties and uses of plastic materials. Think of the various materials youve used in the last day. Cracking oil fractions reaction conditions products equations. Catalytic cracking of hydrocarbons uniwersytet warszawski. This is because alkanes are saturated whereas alkenes are unsaturated which means that they can carry out addition reactions, required for polymerisation. Remember, dont rely on remembering them in the order they appear below as this will not be like an exam. This is a chemical reaction in which heat breaks down long chain molecules into smaller ones. Its a process studied in gcse chemistry, so you need to understand it. More lessons for igcse chemistry math worksheets a series of free igcse chemistry lessons cambridge igcse chemistry.
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