Aqa organic chemistry alkanes modification of alkanes. This organic chemistry note for igcse chemistry will cover the three major homologous series alkane, alkene, and alcohols. Alkenes are unsaturated, have a double bond, have a different general formula, have fewer hydrogen atoms than the corresponding alkane, are more reactive, react with. Apr 08, 2009 isomers of an alkane are two or more alkanes with the same molecular formula but a different structure.
Organic chemistry combustion feel free to leave a feedback. Cracking can be done by various methods including catalytic cracking and steam cracking. This is called catalytic cracking and is an example of a thermal decomposition reaction. An alkene is produced because the original alkane does. Cracking is the process of converting alkanes into alkenes and shorter alkanes. Written by teachers for the edexcel igcse chemistry course. Fractions containing large hydrocarbon molecules are heated at 600 700c to vaporise them. This forms a mixture of straightchain alkanes and alkenes mainly ethene with a small proportion of branched and cyclic hydrocarbons. Ch 4 methane c 2 h 6 ethane c 3 h 8 propane c 4 h 10 butane c 5 h 12 pentane c 6 h 14 hexane c 7 h 16 heptane c 8 h 18 octane c 9 h 20 nonane c 10 h 22 decane. The internal combustion engine produces a number of pollutants including no. This lesson is designed for the new aqa trilogy chemistry gcse, particularly the organic chemistry sow. Choose from 500 different sets of gcse chemistry alkanes flashcards on quizlet. In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby complex organic molecules such as kerogens or longchain hydrocarbons are broken down into simpler molecules such as light hydrocarbons, by the breaking of carboncarbon bonds in the precursors. Alkenes are reactive molecules that are used to make plastics and other chemicals.
Index of gcse igcse oil useful products chemistry revision notes. For example, hexane can be cracked to form butane and ethene. Gcse science chemistry 91 cracking find my revision workbooks here. Gcse chemistry what is the cracking of hydrocarbons.
Organic chemistry teaching resources the science teacher. During cracking, the long molecules break apart, forming smaller alkanes and alkenes. Some of the large hydrocarbons the heavier fractions are broken down into more useful smaller hydrocarbons lighter fractions by a. Gcse chemistry aqa 91 organic chemistry alkanes and alkenes. Gcse chemistry revision questions fossil fuels crude. We crack alkanes because the shorter chain alkanes are more valuable they are used as fuel. You need to understand certain chemical reactions used in a variety of industrial processes for gcse chemistry. Cracking is a very important process used in the petrochemical industry to break down the large hydrocarbons intro smaller hydrocarbons, which burns more easily as fuel. This is achieved by using high pressures and temperatures without a catalyst, or lower temperatures and pressures in the presence of a catalyst. Give a description of how crude oil is formed and where it is found.
Learn about crude oil, hydrocarbons and alkanes with bitesize gcse chemistry aqa. Gcse chemistry senfoundation crude oil, alkanes, frac. Firstly, students asked to think about a question that oil companies face what to do with longer chain hydrocarbons which are in less demand than smaller chain hydrcarbons. What is the name given to the molecules that are found in crude oil. Thermal cracking takes place at high pressure and high temperature and produces a high percentage of alkenes mechanism not required. You need to know about alkanes, alkenes, crude oil and the process of cracking. The rate of cracking and the end products are strongly dependent on the. Gcse chemistry revision science section covering cracking and its products, hydrocarbons, catalyst, thermal decomposition, alkanes, single and. Here youll find thousands of tools and resources, all of which can help you hit the grades youre aiming for. Gcse chemistry revision covering cracking and its products, hydrocarbons, catalyst, thermal decomposition, alkanes, single covalent bonds, alkenes, double covalent bonds, and cracking paraffin. Aqa gcse 91 chemistry 8462 past exam papers and marking schemes, the past papers are free to download for you to use as practice for your exams. Organic chemistry teaching resources worksheets and lesson ideas to challenge students to think hard about crude oil, alkanes and alkenes gcse and key stage 3 the chemistry of carbon compounds is an exciting one.
Give an example of a method by which cracking can be carried out. Catalytic cracking takes place at a slight pressure, high temperature and in the presence of a zeolite catalyst and is used mainly to produce motor fuels and. Cracking is the name given to breaking up large hydrocarbon molecules into. The first ten members of the homologous series of the alkanes are. This page describes what cracking is, and the differences between catalytic cracking and thermal cracking used in the petrochemical industry.
Ch 4 methane c 2 h 6 ethane c 3 h 8 propane c 4 h 10 butane c 5 h 12 pentane c 6 h 14 hexane c 7 h 16 heptane c 8 h 18 octane c 9 h 20 nonane. By the end of this lesson ks5 students should be able to. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Fractions containing large hydrocarbon molecules are. Gcse chemistry revision organic chemistry crude oil.
One of the products of cracking this compound is an alkane which has 10 carbon atoms in it. Learn gcse chemistry alkanes with free interactive flashcards. Designed by expert teachers for the edexcel gcse 91 chemistry syllabus. If you add up the number of hydrogen atoms in the above reaction, you will see that there are 22 on each side. Alkenes alkenes are unsaturated hydrocarbons, meaning they contain a double covalent bond co alkenes are formed through cracking. Cracking of hydrocarbons is illustrated in the below diagram.
Learn about and revise fuels with this bbc bitesize gcse chemistry edexcel study guide. If youre studying for gcse chemistry, then youre in the right place. In chemistry, it is a process of breaking down large alkane into simpler alkenes and alkanes. Gcse chemistry revision science section covering cracking and its products, hydrocarbons, catalyst, thermal decomposition, alkanes, single and double covalent bonds, and cracking paraffin. These resources are specifically designed for senfoundation students studying gcse chemistry ocraqa. Organic chemistry now forms a substantial part of the gcse specifications. Name this chemical and describe a chemical test that could be used to identify between this chemical and the alkane. As part of their work on crude oil, gcse chemistry students will look at thermal cracking. A structured lesson including starter activity, afl work tasks on cracking of alkanes. Gcse chemistry what is the chemistry of the cracking of.
It is the remains of plantsanimalsfossils produced over millions of years. The topics covered in this starter for ten activity are. Cracking allows large hydrocarbon molecules to be broken down into smaller, more useful hydrocarbon molecules. Index of oil and organic chemistry gcseigcseo level. It also produces small alkenes, which are used make many other useful organic chemicals petrochemicals, especially plastics. Apparatus delivery tube and bung bunsen burner boiling tube containing mineral wool porous pot liquid paraffin clamp and stand. Halogenation is the replacement of one or more hydrogens in an organic compound with halogen atoms. Start studying gcse chemistry aqa 91 organic chemistry alkanes and alkenes. Gcse chemistry revision covering cracking and its products, hydrocarbons, catalyst, thermal decomposition, alkanes, single covalent bonds, alkenes, double covalent bonds, and cracking. Petrol and other fuels are produced from it using fractional distillation. The chemistry of cracking results in the formation of smaller, more useful alkanes such as petrol, and even more useful alkenes such as ethene. Cracking hydrocarbons edexcel gcse chemistry revision notes. Organic chemistry starters 1618 resource rsc education. Vapours will then pass over a hot catalyst of silica or alumina.
Combustion of alkanes and other organic compounds can be complete or incomplete. An alkene is produced because the original alkane does not have enough hydrogen atoms to produce two more alkanes. Cracking oil and cracking gcse chemistry single science. Model the industrial process of cracking larger hydrocarbons to produce. Catalytic cracking takes place at a slight pressure, high temperature and in the presence of a zeolite catalyst and is used mainly to produce motor fuels and aromatic hydrocarbons mechanism not required. This experiment models the industrial cracking process. To describe what cracking is and its economic benefits. We will discuss their general formula, physical and chemical properties. There is a greater demand for smaller hydrocarbons than larger ones. Cracking is used to convert long alkanes into shorter, more useful hydrocarbons. Learn about the process of oil distillation in order to create fuels and plastics with bbc bitesize gcse chemistry wjec. Cracking oil fraction hydrocarbons to produce more useful products. Two methods of cracking how to write a balanced equation for cracking what an alkene is, and how they differ from an alkane.
Index of pages on oil, its many useful products, environmental problems and an introduction to organic chemistry doc browns revision notes for gcse, igcse, o level, ks4 science chemistry courses the organic chemistry of carbon compounds is so important that it forms a separate branch of chemistry. Similarly cracking of hydrocarbons includes breaking down of a complex long chain of hydrocarbons into smaller ones. To compare and evaluate the conditions for and the products of thermal and catalytic cracking. Fractions containing large hydrocarbon molecules are heated to vaporise them. Worksheets and lesson ideas to challenge students to think hard about crude oil, alkanes and alkenes gcse and key stage 3 the chemistry of carbon compounds is an exciting one. Cracking an alkane produces a smaller alkane plus an alkene. Alkenes along with alkanes can be produced from cracking. There is a much greater demand for shorter hydrocarbon than there is for the longer hydrocarbons. Lesson planpowerpoint to teach cracking of alkanes. Alkanes crude oil, hydrocarbons and alkanes aqa gcse. Whereas alkenes produce a smoky yellow flame as they dont fully combust. The fractional distillation of crude oil produces alkanes. Introduction to cracking a problem of supply and demand and other products. Targeted towards aqa c1 topic 5 but suitable for edexcel and other exam boards too.
After watching the covalent bonds video you should have sufficient knowledge to understand about how alkanes and alkenes are formed and the differences. Bookmark file pdf chemistry answer sheet hydrocarbons previous year neet examinations. The american chemist, william burton, is usually credited with being the inventor of the thermal cracking process. They cover formation of crude oil, hydrocarbons, alkanes, fractional distillation, alkenes and polymerisation. As well as using a normal type of molecular formula to describe an organic molecule, they can be represented by drawing out their structure i. The best way to remember the information in this chapter is to get a pen and paper and write down your answers before clicking on the answer link which will take you to the correct page you may have to read through some of the page before you find the answer. High octane starter to inject pace which is easily adapted for other lessons. A hydrocarbons are broken down 1 mark to produce smaller more useful molecules 1 mark. Outline of practical work is included but follow centre basedcleaps safety guidelines.
We crack alkanes because the shorter chain alkanes are more valuable they. Cracking hydrocarbons in liquid paraffin with a catalyst. Cracking larger hydrocarbons produces smaller alkanes that can be converted into petrol. Cracking is the name given to breaking up large hydrocarbon molecules into smaller and more useful bits. Start off by using the study planner, a great tool that can automatically work out how much time you need to spend on your chemistry work while balancing it. What hydrocarbons are what alkanes are the general formula for alkanes an example of using that. The cracking of hydrocarbons can make alkanes and one other type of chemical. Gcse science chemistry 91 crude oil and hydrocarbons duration. Thermal cracking uses harsh conditions like high temperature and high pressure.
Why is it that organisms on earth have evolved to be organic chemistry teaching resources read more. As bond breaking is a random process, a variety of products can be formed. Cracking of alkanes craking refers to the process where cc bonds in long chain alkanes molecules are broken, producing smaller molecules of alkanes and alkenes. C 16 h 34 is an alkane which can be used as the starting chemical in cracking. Hydrocarbons can be broken down cracked to produce smaller, more useful molecules. In this video, we look at how cracking is used to convert longchain hydrocarbons into shorterchain hydrocarbons. Start studying igcse chemistry alkanes and alkenes. Cracking and alkenes crude oil, hydrocarbons and alkanes. Cracking hydrocarbons in liquid paraffin with a catalyst resource. Gcse chemistry revision science section covering cracking and its products, hydrocarbons, catalyst, thermal decomposition, alkanes, single and double.
Cracking and alkenes gcse chemistry single science revision. Students should be able to explain the economic reasons for cracking alkanes. One of these is thermal cracking which is used on crude oil. In addition to this you will need to know about functional groups such as alcohols, carboxylic acids and esters and how to draw their structures. Two methods of cracking how to write a balanced equation for cracking what an alkene is, and how they differ from an alkane the test for alkenes the. Chemistry revision notes on the topic cracking hydrocarbons. Aug 06, 2019 a structured lesson including starter activity, afl work tasks on cracking of alkanes. As chemistry aqa cracking alkanes teaching resources.
This is a thermal decomposition reaction known as cracking. Long chain hydrocarbons can be broken into smaller hydrocarbons, by heating with a catalyst. Thermo cracking is used to break down high molecular mass alkanes into low molecular mass alkanes as well as alkenes using heat and a catalyst. Best igcse organic chemistry notes complete breakdown. Hydrocarbons from oil a2levellevelrevision, chemistry. Gcse crude oil revise the thermal cracking reaction. Cracking meaning types of cracking organic chemistry. Organic chemistry introduction 1 structural formulae. Please comment if you have any questions, and subscribe if you. Organic chemistry is the study of compounds based on hydrocarbons and their derivatives. Doc browns gcseigcseo level ks4 sciencechemistry revision notes.
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