Thermal cracking breaks cc bonds by homolytic fission forming free radicals. The gcse chemistry curriculum is substantial, so its vital to get organised when starting your revision period. What is organic chemistry, homologous series, what are alkanes, what are isomers, properties of alkanes, cracking hydrocarbons, what are alkenes, isomers in alkenes, what are alcohols. This is done by heating the hydrocarbon in the presence of a catalyst. 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. Gcse chemistry revision organic chemistry crude oil.
Crude oil is a mixture of substances which are mostly hydrocarbons a hydrocarbon is a compound containing hydrogen and carbon only remember the above sentence, you will probably need it in the exam. This page also contains the link to the notes and video for the revision of this topic c9. Igcse organic chemistry solutions, examples, worksheets. Crude oil is a dark smelly liquid which is a mixture of many different. 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 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. Gcse chemistry what is the chemistry of the cracking of. Cracking and alkenes crude oil, hydrocarbons and alkanes aqa. Oldsetaqa gcse chemistry topic 610 paper 2 flashcards. Ks4 aqa gcse chemistry science cracking hydrocarbons lesson. Cracking hydrocarbons edexcel gcse chemistry revision notes.
Gcse science chemistry 91 crude oil and hydrocarbons duration. The name given to hydrocarbons with at least one double bond is. Gcse chemistry aqa 91 organic chemistry alkanes and alkenes. Cracking hydrocarbons on a microscale resource rsc. Alternatively, we can mix the hydrocarbon vapor with very hot steam. The chemistry of the cracking of hydrocarbons including the conditions and catalyst thermal. Cracking produces saturated hydrocarbons which are used as fuels.
Some of the large hydrocarbons the heavier fractions are broken down into more useful smaller hydrocarbons lighter fractions by a process known as cracking. See also the dehydration of ethanol to produce ethene. Describe the production of materials that are more useful by cracking. Start studying oldsetaqa gcse chemistry topic 610 paper 2. Please comment if you have any questions, and subscribe if you. We then pass the vapor over a hot catalyst, to speed up the reaction. The cracking of hydrocarbons can make alkanes and one other type of chemical. Learn about crude oil, hydrocarbons and alkanes with bitesize gcse chemistry aqa. Why is porous pot catalyst used in cracking hydrocarbons.
Cracking is the most important process for the commercial production of gasoline and diesel fuel. All that we need to do is heat longchain hydrocarbons, so that they turn into vapor. And be careful with your phrasing cracking produces alkenes and shorter chain alkanes. Liquid paraffin a mixture of alkanes of chain length c20 and greater is vaporised and passed over a hot pumice stone catalyst. Cracking is the process of converting alkanes into alkenes and shorter alkanes. Organic chemistry now forms a substantial part of the gcse specifications.
The chemistry of cracking results in the formation. Plant and animal cells, eukaryotic and prokaryotic cells, bacteria, structures in a typical plant and animal cell, specialised cells, xylem and phloem, cell differentiation, microscopy, scanning electron microsopes, growing bacteria using agar plates, cell division. The industrial process of fractional distillation separates crude oil into fractions, some of these fractions can be used for fuels and plastics. Cracking is the name given to breaking up large hydrocarbon molecules into smaller and more useful bits. In the ball and stick models below, carbon atoms are black and hydrogen atoms are white. Fuels made from oil mixtures containing large hydrocarbon.
It is caused by the breaking of carboncarbon bonds. As well as alkanes, what other group of hydrocarbons are made as a result of cracking. Gcse chemistry what is the cracking of hydrocarbons. Written by teachers for the cie igcse chemistry 91 course.
There is a greater demand for smaller hydrocarbons than larger ones. 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. Aqa gcse 91 chemistry quiz on topic 7 organic chemistry. Organic chemistry ks4gcse chemistry teaching resources. What is the name of the process by which large hydrocarbons are broken up into smaller, more useful molecules. Catalytic cracking processes heavy longchain fractions obtained in larger quantities than required. Name two types of cracking and explain why scientists might want to crack hydrocarbons. For example, lower alkanes for petrol or alkenes for making plastics. Catalytic cracking breaks cc bonds by heterolytic fission forming ions. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Free biology animations blood clotting animation food groups drag and drop. Crude oil is a mixture of hydrocarbons hydrocarbons are compounds that contain hydrogen and carbon atoms only.
Crude oil is described as a fossil fuel but it is much more important than that as many plastics have crude oil as a raw material. The nobel school, stevenage, mobbsbury way, sg2 0hs phone. Cracking edexcel igcse chemistry notes save my exams. Because alkenes are hydrocarbons with at least one carboncarbon double bond the alkene homologous series starts at ethene c 2 h 4. You need to know about alkanes, alkenes, crude oil and the process of cracking. The process of cracking can be conducted on the long chain hydrocarbon. Start studying gcse chemistry aqa 91 organic chemistry alkanes and alkenes. The compounds are named as for the alkanes, but with the ending, ene instead of ane. A gaseous product is obtained which is flammable and which will.
Conditions catalyst thermal decompositiongcsescience. Hydrocarbons from oil a2levellevelrevision, chemistry. Crude oil can be converted into many useful things. Studying for the gcse chemistry exam might seem scary to begin with, but there are plenty of steps students can take to make sure they are fully prepared. Cracking fuels edexcel gcse chemistry single science. The rate of catalyst greatly depends upon the factors such as the presence of catalyst and temperature. Cracking hydrocarbons in liquid paraffin with a catalyst. Ks4 aqa gcse chemistry science cracking hydrocarbons. Cracking is the name for a thermal decomposition processes. The purpose of this process is to get the simpler molecules from the complex organized molecules.
This lesson is designed for the new aqa trilogy chemistry gcse, particularly the organic chemistry sow. So what is cracking it is when big hydrocarbon molecules are broken down into smaller ones. Cracking and alkenes crude oil, hydrocarbons and alkanes. Given the following cracking equation, what is the missing molecule. The porous pot that is used in a lab, is used to facilitate the cracking process during heating, the porous pot is used as a catalyst to speed up the cracking process. The name given to hydrocarbons with at least one triple bond is. Stick with shorter as opposed to short because if you crack a larger alkane you could end up with an alkane as a product that you wouldnt normally describe as short. Cracking of ethane and propane to produce ethylene. Targeted towards aqa c1 topic 5 but suitable for edexcel and other exam boards too. Facts about cracking hydrocarbons present the information about a process of cracking employed in the chemistry and petroleum geology. Do not forget the word only at the end since crude oil is a mixture of different hydrocarbon compounds, the different hydrocarbons will have. Gcse chemistry what is the chemistry of the cracking of hydrocarbons.
The name given to hydrocarbons with single bonds only is. Pressure and steam an interesting aspect of ethene production. In this video, we look at how cracking is used to convert longchain hydrocarbons into shorterchain hydrocarbons. The fractional distillation of crude oil produces alkanes. Cracking is used to convert long alkanes into shorter, more useful hydrocarbons. This means that large hydrocarbon molecules break into smaller molecules when they are heated. Hydrocarbons can be broken down cracked to produce smaller, more useful molecules. Cracking or thermal decomposition is used in the oil industry to convert higher fractions of hydrocarbons into more useful molecules. Bp educational service hydrocarbons from crude oil. Schematic diagram of a fluid catalytic cracking unit. This slideshow covers the content from the cell biology topic in the 2016 aqa syllabus. The carbon atoms in these molecules are joined together in chains and rings. This page contains the aqa gcse chemistry c9 hydrocarbons questions and kerboodle answers for revision and understanding hydrocarbons.
Cracking oil fraction hydrocarbons to produce more useful products. The petrochemical industry, pressure and steam in ethene production activity 3. Cracking meaning types of cracking organic chemistry. 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.
Reforming is described as the processing of straightchain hydrocarbons into branchedchain alkanes and cyclic hydrocarbons for efficien gcse. Cracking of hydrocarbons involves thermal decomposition. Cracking is simply splitting of larger molecules to simpler ones. Chemical and material behaviour bookmark resources cracking animation animation. What is the cracking of hydrocarbons after the fractional distillation of crude oil there are too many large hydrocarbons and not enough small hydrocarbons to meet the publics demand. The rate of cracking and the end products are strongly dependent on the temperature and presence of catalysts. The general formula for the homologous series of alkenes is cnh2n where n is the number of carbon atoms. Explain how cracking involves the breaking down of larger, saturated hydrocarbon molecules alkanes into smaller, more useful ones, some of. This is achieved by using high pressures and temperatures without a catalyst, or lower temperatures and pressures in the presence of a catalyst. Petrol and other fuels are produced from it using fractional distillation. 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. The petrochemical industry, the industrial production of ethene activity 2. The hydrocarbons are boiled and the hydrocarbon gases are either mixed with steam and heated to a very high temperature.
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