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