Experimental chemistry particulate nature of matter acids bases salts properties and uses of ammonia sulphuric acid stoichiometry and the mole concept introduction to organic chemistry alkanes alkenes alcohols. Cracking meaning types of cracking organic chemistry. Free o level chemistry revision notes that will help you in revising for your exams. Cracking of the unbranched compound e, c6h14, produced the. Cracking is the process whereby long and medium chain hydrocarbons are heated and break apart giving short chain alkanes, alkenes and hydrogen. The molecules are broken up in a random way which produce a mixture of alkanes and alkenes. Cracking and alkenes crude oil, hydrocarbons and alkanes aqa. Cracking and alkenes gcse chemistry single science revision. You can find instructions for this experiment at resourceres00000681crackinghydrocarbons liquid paraffin. Cracking allows large hydrocarbon molecules to be broken down into smaller, more useful hydrocarbon molecules. Explore over 400 exciting practical experiments for your classroom. The worksheet can also be found by clicking on the worksheet below. Year 12 lesson graded outstanding to teach cracking. Aqa a level chemistry flashcards decks in this class 88.
Cracking produces the smaller hydrocarbons which make up petrol gasoline. Oxford aqa international a level chemistry answers. Chemistry catalytic cracking help related articles a level chemistry help lastminute a level chemistry revision. Cracking hydrocarbons in liquid paraffin with a catalyst. Also check out our other helpful revision resources for o level chemistry 5070. Engaging video tutorials for the new ocr, aqa and edexcel spec. Practical chemistry activities are accompanied by our standard health and safety guidance. Simply put, hydrocarbon cracking is the process of breaking a longchain of. Cracking is the breaking down of an unsaturated hydrocarbon into smaller hydrocarbons. Hydrocarbons from oil a2levellevelrevision, chemistry.
Aqa alevel chemistry fractional distillation and cracking. Sections also exist to cover the legacy ocr a chemistry and the west african senior secondary chemistry specifications. Semih eser, professor of energy and geoenvironmental engineering, college of earth and mineral sciences, penn state. This site contains notes, exercises, exam questions and tests to cover the new aqa a level chemistry course. Cracking of the unbranched compound e, c6h14, produced the saturated compound f and an unsaturated compound g mr 42. Alkanes alevel chemistry ocr, aqa, edexcel youtube. Cracking is the process of breaking longer chained alkanes down into smaller alkanes and alkenes, sometimes for polymer manufacture, and sometimes to improve octane number. As chemistry aqa cracking alkanes teaching resources.
This video runs through alkanes, alkenes and haloalkanes followed by fractional distillation and cracking. Cracking oil fraction hydrocarbons to produce more useful products. In petroleum refining, this process is used in the production of petrol, diesel, and gasoline. Cracking chemistry is a text book i wrote to address the everincreasing need for a suitable textbook to go along with my teachings of chemistry as a subject at school as well as to fill the void of an easily understandable,well written. C 16 h 34 is an alkane which can be used as the starting chemical in cracking. Similarly cracking of hydrocarbons includes breaking down of a complex long chain of hydrocarbons into smaller ones. Doc browns gcseigcseo level ks4 sciencechemistry revision notes oil. To compare and evaluate the conditions for and the products of thermal and catalytic cracking. In this video well look at the process of industrial cracking. Covers thermal and catalytic cracking, ppt file, application questions, answers and an assessed homework activity with mark scheme. Wikipedia a good overview of industrial processes for hydrocarbon cracking. This is a dangerous scientific experiment and must not be attempted without skilled supervision.
O level chemistry revision notes archives teachifyme. Petrol gasoline contains a mixture of hydrocarbons, with 5 to 10 carbon atoms, but the products of fractional distillation do not completely suit the desired mixture for a. To describe what cracking is and its economic benefits. A brief description of the difference between thermal and catalytic cracking of alkanes. There are many websites, but few deal with this topic at the 14 18 chemistry teaching and learning level most are either far too technical or too elementary. Graded with a video link and mark schemes for everything.
A cracking practical can be carried out in a school lab quite easily by using a broken pottery as a catalyst. Unlock the full a level chemistry course at created by ella buluwela, chemistry expert at snaprevise. By the end of this lesson ks5 students should be able to. Reforming, in chemistry, processing technique by which the molecular structure of a hydrocarbon is rearranged to alter its properties. In an exam, you could just as well be asked to make up your own. Resources and inspiration for practical work and demonstrations. Cracking and alkenes crude oil, hydrocarbons and alkanes. Cracking edexcel igcse chemistry notes save my exams. Introduction to cracking a problem of supply and demand and other products. Depending on the end product, the oils can go directly into fuel blending, or they can be routed through further cracking reactions or other. Identify these compounds and write an equation for the reaction. Catalytic cracking processes heavy longchain fractions obtained in larger quantities than required. This video shows an overview about cracking paraffin. Cracking is the process of breaking up the long chain hydrocarbons which are in high supply but low demand, into short chain hydrocarbons that are in low supply but high demand.
Cracking is a type of chemical reaction in which hydrocarbon molecules. The process of breaking higher hydrocarbons with high boiling points into a variety of lower hydrocarbons that are more volatile low boiling, is called cracking or pyrolysis. 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. Aqa a level chemistry modification of alkanes by cracking. The purpose of cracking is to produce high demand hydrocarbons. Cracking chemistry has been listed as a level 5 vital article in an unknown topic. That is so that you can mark your answers more easily. Pupils can share their ideas in pairs, then as a class, before being introduced to the process of cracking.
This is a thermal decomposition reaction known as cracking. Chemguide a discussion of the cracking of hydrocarbons for alevel chemistry students and teachers. The process is frequently applied to lowquality gasoline stocks to improve their combustion characteristics. For example, a higher hydrocarbon c 1 0 h 2 2 splits according to the reaction. Mechanism for thermal cracking a level chemistry the. In chemistry, it is a process of breaking down large alkane into simpler alkenes and alkanes. This forms a mixture of straightchain alkanes and alkenes mainly ethene with a.
A level chemistry ocr textbook answers edexcel asa level chemistry student book 1 answers kerboodle ocr as chemistry breadth mon 20th may unofficial markscheme. Catalytic cracking breaks cc bonds by heterolytic fission forming ions. Model the industrial process of cracking larger hydrocarbons to produce smaller. Thermal cracking takes place at high pressure and high temperature and produces a high percentage of alkenes mechanism not required. Heat a known mass of two metals to produce their oxides and. The mechanism is free radical and it is difficult to control the composition of the products, which are mixtures of short chain alkanes and alkenes.
This is expensive as the hydrocarbons are subject to high temperature and pressure. Learn vocabulary, terms, and more with flashcards, games, and other study tools. This website and its content is subject to our terms and conditions. Thermal cracking breaks cc bonds by homolytic fission forming free radicals. These notes on cracking alkanes to make alkenes for plastics and other products from cracking like petrol and diesel fuels are designed to meet the highest standards of knowledge and understanding required for studentspupils doing gcse chemistry, igcse chemistry, o level chemistry. To help you check your progress and understanding, the answers for the end of chapter questions in international a level chemistry for oxford international aqa examinations are available here. 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. It also produces high proportions of branched alkanes and aromatic hydrocarbons like benzene. The zeolites used in catalytic cracking are chosen to give high percentages of hydrocarbons with between 5 and 10 carbon atoms particularly useful for petrol gasoline. Fractions containing large hydrocarbon molecules are heated to vaporise them.
This statement is about the use of cracking to make smaller and more useful. Cracking is the starting point for the manufacture of many organics. A structured lesson including starter activity, afl work tasks on cracking of alkanes. Cracking chemstuff chemstuff mr bankss chemistry site.
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