They should try to learn that fractional distillation is a separation process, whereas cracking is a chemical reaction. Gcse science chemistry 91 triple condensation polymers duration. Ethene is heated up to about 200 degrees celsius under a pressure of about atmospheres in the presence of. Cracking produces smaller, more useful hydrocarbon molecules. Cracking meaning types of cracking organic chemistry. Nov 14, 2017 gcse science chemistry 91 crude oil and hydrocarbons. To familiarise you with it, weve created this interactive quiz. Gcse chemistry what is the polymerisation of ethene. Fractional distillation of crude oil produces useful fractions and notsouseful fractions. Gcse chemistryscience 5ch1f01 7 question 2 a this question was answered quite well. This is achieved by using high pressures and temperatures without a catalyst, or lower temperatures and pressures in the presence of a catalyst. The fraction produced from crude oil is heated to form a gas. Our core activities are designed to develop the skills theyre learning in school to build your childs confidence. We can break down hydrocarbons in a process called cracking.
Gcse polymerisation revise reaction of monomer molecules. Cracking allows large hydrocarbon molecules to be broken down into smaller, more useful hydrocarbon molecules. Monomers and polymers a polymer is a compound comprising very large molecules that are multiples of simpler chemical units called monomers. Alkenes are reactive molecules that are used to make plastics and other chemicals. Sometimes, hydrogen is also produced during cracking. This type of polymerisation is called addition polymerisation.
Learn the basics about the cracking of hydrocarbons and why it is done. The double bond in an alkene like ethene can be broken open and joined to other molecules see the chemistry of polymerisation. 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. Pearson edexcel certificate pearson edexcel international. Gcse chemistry definitions when learning definitions i find it easier to move around and say them to yourself.
Poli many greek, meros 1 part of a whole greek, polymer large unit made up of many identical small units. Depending on the end product, the oils can go directly into fuel blending, or they can be routed through further cracking reactions. Polymerisation and cracking gcse science marked by teachers. Cracking of petroleum yields light oils corresponding to gasoline, middlerange oils used in diesel fuel, residual heavy oils, a solid carbonaceous product known as coke, and such gases as methane, ethane, ethylene, propane, propylene, and butylene. Cracking is normally carried out at high temperatures using a catalyst. Cracking is the most important process for the commercial production of gasoline and diesel fuel.
They are formed when many small molecules join together. Polymerisation and cracking gcse science marked by. Thousands of english, maths, science gcse revision activities created by teachers accelerate your childs learning with our learn, practise and test approach. Addition polymerisation occurs between polymers that a double covalent bond. Alkenes are reactive and so are useful for making many other substances including polymers polymers have very large molecules. Condensation polymerisation involves a reaction between monomers with two different functional groups. The polymerisation of ethene the double bond in an alkene like ethene can be broken open and joined to other molecules see the chemistry of polymerisation a molecule of ethene can be joined to another molecule of ethene. 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. Cracking converts large alkane molecules into smaller, more useful, alkane and alkene molecules. A chemical reaction is a process where the molecular structure changes. Written by teachers for the cie igcse chemistry 91 course. Polymerisation is a process in which small units called monomers are combined to form a large macromolecule called a polymer.
Making crude oil usefulfractional distillation and cracking. Addition polymerisation involves addition reactions in which a large number of small molecules monomers join together to form very large molecules polymers. Some of the smaller hydrocarbons formed by cracking are used as fuels, and the alkenes are used to make polymers in plastics manufacture. A short videoaudio guide explaining the essentials of cracking and polymerisation. It is the principal industrial method for producing the lighter alkenes or commonly olefins, including ethene or ethylene and propene or propylene. As you can see in the video opposite, cracking needs a catalyst and a high temperature. Gcse chemistry revision worksheets chemistry past papers. In this episode, he will look at the different molecular forces in substance and how they affect their properties. Its made when propene undergoes polymerisation and is also called polypropylene. They are also the precursor in the production of many types of plastics and resins via polymerisation reactions. Thousands of gcse english, maths and science activities.
What are the differences between cracking and polymerisation. It is like a catalyst, except it gets used up in the reaction. At fuse school, teachers and animators come together to make fun. In addition polymerisation the monomers have at least one double bond between carbon atoms. The conditions used for polymerisation are heat, pressure and a catalyst. A molecule of ethene can be joined to another molecule of ethene. Addition polymerisation condensation polymerisation in addition polymerisation, alkenes add to themselves. New materials are often used to replace older ones because the new material has superior properties. Cracking and alkenes crude oil, hydrocarbons and alkanes. As this addition proceeds further a long molecular chain is formed. Oct 03, 2015 a short videoaudio guide explaining the essentials of cracking and polymerisation. Hence addition polymerisation is the process of forming a giant structure from many small structures adding together.
Candidates should learn the spelling of scientiic words. The properties of the material depend on what the polymer is made from and its. Polymers chemistry alevel revision gcse and alevel. Cracking hydrocarbons edexcel gcse chemistry revision notes. During cracking, the long molecules break apart, forming smaller alkanes and alkenes. Dec 04, 2009 what are the differences between cracking and polymerisation. Many are very useful, such as cooking and combustion. 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. The process of monomers small molecules joining up to form a polymer long molecule is called polymerisation.
The chain length of the polymer varies from about 2000 to 40,000 carbon atoms. Addition and condensation polymerisation polymers are macromolecules that consist of building blocks called monomers. There is a greater demand for smaller hydrocarbons than larger ones. Please comment if you have any questions, and subscribe if you. It is the principal industrial method for producing lighter alkenes olefins, including ethene or ethylene and propene or propylene figure 3.
Fractions containing large hydrocarbon molecules are heated to vaporise them. Quite a lot of candidates confused cracking and fractional distillation. Learn and revise polymers with bbc bitesize for gcse design and technology. Edplaces pearson edexcel single science gcse activities, exam style questions and practice papers covers content from gcse biology, gcse chemistry and gcse physics specifications. In the process, the second ethene molecule has its double bond broken, and this may be added to a third molecule of ethene, and so on. Steam cracking is a petrochemical process in which saturated hydrocarbons are broken down into smaller, often unsaturated, hydrocarbons. Addition polymerisation is the name given to a chemical reaction in which unsaturated monomers are joined, forming a polymer. We can see many reactions such as fireworks and explosions. What are the conditions for condensation polymerisation. Elastic fibres used to make lycrahydrogel dressings keep wounds moistdental polymers used for resin tooth fillingsmattresses made from memory foam mould to body shape. In the process, the second ethene molecule has its double bond broken, and this may be added to a third molecule of. This is because alkanes are saturated whereas alkenes are unsaturated which means that they can carry out addition reactions, required for polymerisation.
Cracking and polymerisation video teaching resources. The alkenes can then undergo polymerisation to make polymers such as plastics while the shorter alkanes are typically used for fuel. Cracking and alkenes gcse chemistry single science revision. Polymers igcse chemistry solutions, examples, worksheets. Cracking is the name given to breaking up large hydrocarbon molecules into smaller and more useful bits. But when some of the fractions of crude oil are cracked, a whole new world of chemistry opens up. Polymers produce a very wide range of materials with many uses. Unsaturated monomers alkenes can open up their double covalent. What are some differences between cracking and polymerisation. Each polymerisation reaction also requires something to start the process, called an initiator.
Some are common sense but make sure to test yourself afterward as at least 10 marks in every test will go to definitions. Oldsetaqa gcse chemistry topic 610 paper 2 flashcards. It is caused by the breaking of carboncarbon bonds. Step a weigh an empty evaporating basin step b transfer 50 cm3 of sea water into the basin step c heat the sea water in the basin until all the water has evaporated step d allow the basin and residue to. Learn about crude oil, hydrocarbons and alkanes with bitesize gcse chemistry aqa. Its written by teachers especially to help year 10 and year 11 students revise. There are two types of polymerisation processes, one is addition polymerisation and the other is condensation polymerisation. The reason for this is that cracking produces a new family of. Petrol and other fuels are produced from it using fractional distillation. The rate of catalyst greatly depends upon the factors such as the presence of catalyst and temperature. Fractional distillation of crude oil and cracking produces a large array of hydrocarbons.
Oldsetaqa gcse chemistry topic 610 paper 2 quizlet. Steam cracker units are facilities in which a feedstock such as naphtha, liquefied. You may use each word once, more than once or not at all. Start studying oldsetaqa gcse chemistry topic 610 paper 2. Remember, dont rely on remembering them in the order they appear below as this will not be like an exam. Targeted towards aqa c1 topic 5 but suitable for edexcel and other exam boards too. Gcse science chemistry 91 crude oil and hydrocarbons. Edplaces gcse examstyle questions and practice papers help your child hone their examtechnique and prepare them for anything the exam may throw at them. Unsaturated monomers alkenes can open up their double covalent bonds and join together to make polymer chains. 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. In industry they use silica silicon oxide or alumina aluminium oxide. For the polymerisation of ethane, you require a temperature of 200oc, a pressure of 2000 atmospheres.
Its a process studied in gcse chemistry, so you need to understand it. Petrochemicals and polymers, petroleum, alternative fuels and energy sources, addition polymerisation, condensation polymerisation. Process of joining small molecules, called monomers, to form very large long molecules, called polymers. This is called catalytic cracking and is an example of a thermal decomposition reaction.
The following diagrams show addition polymerisation polyethene and condensation polymerisation polyamide, polyester. Examiners report november 2011 gcse chemistryscience 5ch1f01. 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. Cracking is used to convert long alkanes into shorter, more useful hydrocarbons.
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