Learn vocabulary, terms, and more with flashcards, games, and other study tools. This is achieved by using high pressures and temperatures without a catalyst, or lower temperatures and pressures in the presence of a catalyst. Cracking creates more useful hydrocarbons from less useful hydrocarbons by breaking down long chain alkanes into shorter chain molecules of alkane and alkene. In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby. Cracking and alkenes crude oil, hydrocarbons and alkanes aqa. Lesson with option of differentiated resources for cracking hydrocarbon fuelsfractions. Cracking is used to convert long alkanes into shorter, more useful hydrocarbons. Ks4 aqa gcse chemistry science cracking hydrocarbons. Alkenes are a family of hydrocarbon compounds with the general formula c nh 2n, for example, c2h4 ethene. When the hydrocarbon molecules are broken up in a random way as a product a mixture of shorter hydrocarbons chains is expected. Please comment if you have any questions, and subscribe if you. This lesson was originally designed for the aqa gcse 91 chemistry specification but is easily transferable to other specifications including ks3 as a challenge lesson and ks5 as a recap lesson. We also look at alkenes and how we test for alkenes using bromine water. Learn about crude oil, hydrocarbons and alkanes with bitesize gcse chemistry aqa.
Cracking breaks longchain hydrocarbons into short chain hydrocarbons which are more useful. 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. Designed by expert teachers for the edexcel gcse 91 chemistry syllabus. This means that large hydrocarbon molecules break into smaller molecules when they are heated. Fractions containing large hydrocarbon molecules are. Cracking is a thermal decomposition process by which large alkane hydrocarbon molecules are broken down by passing them over a heated catalyst at high pressure. You tend to get molecules containing benzene rings and short hydrocarbons. Model the industrial process of cracking larger hydrocarbons to produce smaller alkanes that can be converted into petrol.
The complete combustion of a hydrocarbon produces and. Give an example of a method by which cracking can be carried out. The hydrocarbons are boiled and the hydrocarbon gases are either mixed with steam and heated to a very high temperature or passed over a hot powdered aluminium. Cracking is the name given to breaking up large hydrocarbon molecules into. Cracking hydrocarbon chains will be expected for all three exam boards which are aqa. Apart from alkenes and alkanes what else is made during the process of cracking.
A hydrocarbons are broken down 1 mark to produce smaller more useful molecules 1 mark. Cracking hydrocarbons edexcel gcse chemistry revision notes. Petroleum as a source of hydrocarbons by fractional. Gcse chemistry crude oil and alkanes aqa 91 duration. Cracking breaks large hydrocarbon molecules down into smaller, more useful molecules. Simply put, hydrocarbon cracking is the process of breaking a longchain of hydrocarbons into short ones. We crack alkanes because the shorter chain alkanes are more valuable they. Gcse chemistry what is the cracking of hydrocarbons. Cracking is the process of converting alkanes into alkenes and shorter alkanes. The mechanism of catalytic cracking of hydrocarbons is ionic. As well as alkanes, what other group of hydrocarbons are made as a result of cracking. Petrol and other fuels are produced from it using fractional distillation.
Learn the basics about the cracking of hydrocarbons and why it is done. In this video, we look at how cracking is used to convert longchain hydrocarbons into shorterchain hydrocarbons. 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. Some of the large hydrocarbons the heavier fractions are broken down into more useful smaller hydrocarbons lighter fractions by a process known as cracking. Before joining or doing any activity please read the guidelines of the. Alkenes along with alkanes can be produced from cracking. Polymers, monomers, crude oil, cracking and hydrocarbons. Cracking hydrocarbons in liquid paraffin with a catalyst.
Chemistry 5 cracking hydrocarbons gcse core flashcards. Last time, i was looking at what features make up a letter, trying to define the ineffable qualities of letterness so that you arent relying on simply sticking an address at the beginning, along with a. A brief description of the difference between thermal and catalytic cracking of alkanes. Gcse chemistry 6 cracking hydrocarbons no rude comments please. Try this microscale approach it guarantees crack results every time. 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. After the fractional distillation of crude oil there are too many large hydrocarbons and not enough small hydrocarbons to meet the publics demand. Norsk nynorsk polski portugues romana simple english slovencina slovenscina slunski. The cracking of hydrocarbons makes petrol and ethene. Includes a couple of videos summarising the process cracking, and testing for alkenes. There are two good economic reasons for cracking oil fractions i there isn.
Top 5 college degrees that are actually worth it 2020 duration. 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. Cracking hydrocarbons cracked to produce smaller more useful molecules. This resource is a lesson with activities covering the cracking hydrocarbons section of the 2015 aqa gcse chemistry specification. Cracking is the name given to breaking up large hydrocarbon molecules into smaller and more useful bits. Written by teachers for the edexcel igcse chemistry course. This video prepares students for gcse higher tier science. Are larger hydrocarbons more or less viscous than smaller hydrocarbons. Gcse chemistry revision science section covering cracking and its products, hydrocarbons, catalyst, thermal decomposition, alkanes, single and double covalent bonds, and cracking paraffin. Gcse chemistry revision covering cracking and its products, hydrocarbons, catalyst, thermal decomposition, alkanes, single covalent bonds, alkenes, double covalent bonds, and cracking paraffin. Some of the large hydrocarbons the heavier fractions are broken down into more useful smaller hydrocarbons lighter fractions by a. Cracking and alkenes crude oil, hydrocarbons and alkanes. What is the chemistry of the cracking of hydrocarbons cracking of hydrocarbons involves thermal decomposition.
The rate of cracking and the end products are strongly dependent on the temperature and presence of catalysts. In addition except, catalytic cracking reactions of isomeryzation, cyclization, polymerization, dehydrogenation and others are also possible. Cracking a hydrocarbon produces two new hydrocarbons a and b. Bromine water added to b turns from an orange solution to colourless. Take a look at our interactive learning flashcards about chemistry 5 cracking hydrocarbons gcse core, or create your own flashcards using our free cloud based flashcard maker. Igcse chemistry past exams, tutorials, notes and more on nada ak is lecturing. Products of cracking hydrocarbons the products of catalytic cracking include smaller alkanes and alkenes. Petroleum as a source of hydrocarbons by fractional distillation and cracking. The process is done at high temperature and pressure. Industrial processes such as cracking and reforming use these fractions to make hydrocarbons, which are in short supply. Gcse chemistry what is the chemistry of the cracking of. Chemistry revision notes on the topic cracking hydrocarbons. During combustion, the and in the fuels are oxidised. Cracking oil and cracking gcse chemistry single science.
Targeted towards aqa c1 topic 5 but suitable for edexcel and other exam boards too. At fuse school, teachers and animators come together to make fun. Balance the equation for the complete combustion of this hydrocarbon. Includes what cracking is and why it is useful, conditions for thermal and catalytic cracking, testing for alkenes and completing cracking equations. There is a greater demand for smaller hydrocarbons than larger ones. Revision homework cracking hydrocarbons the production of some products of fractional distillation of crude oil, such as naphtha, fuel oil and bitumen, exceeds demand. A lesson covering cracking hydrocarbons as part of the organic chemistry unit key stage 4, aqa. High octane starter to inject pace which is easily adapted for other lessons. Why is porous pot catalyst used in cracking hydrocarbons. Catalytic cracking of hydrocarbons uniwersytet warszawski. First, crack the vapour of liquid paraffin by passing it over a heated catalyst to produce and collect a mixture of gaseous shortchain hydrocarbons.
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