Cracking involves breaking down larger crude oil fractions into smaller more useful hydrocarbons. This reaction involves heating the crude oil fraction to a high temperature so that it vaporises. The vapour is then passed over a catalyst or mixed with steam. Cracking is a thermal decomposition reaction - large molecules are broken into smaller molecules using heat Here is an example of cracking: 800°C + Catalyst C 10 H > C 5 H 12 + C 3 H 6 + C 2 H 4 Decane Pentane Propene Ethene Bromine water can be used to test a compound to see if its an alkane or alkene. It stays orange if a compound is saturated. It turns colourless if a compound is unsaturated. Crude oil can be used to make plastics using a process called polymerisation. This process involves joining together small molecules known as monomers into large molecules known as polymers. C1 Products from oil Polymerisation of ethene can represented like this: Biodegradable plastics are made partly using corn starch, which microorganisms feed on to break it down. However, growing corn starch for fuel and plastics could raise food prices, destroy habitats and cause global warming. Ethanol is an alcohol. Ethanol for use in drinks is made by fermentation of sugar using yeast: sugar >ethanol + carbon dioxide The ethanol is produced in batches and gives off CO 2, a greenhouse gas. Ethanol for use as a fuel or a solvent can be made from ethene and steam. This is a hydration reaction. It does not give off CO 2 and is a continuous process. However, ethene comes from crude oil, which means it is a non-renewable production method. Alkenes are produced during cracking. These are unsaturated hydrocarbons which means they contain a double bond. Their general formula is CnH 2 n Ethene Propene (C 2 H 4 ) (C 3 H 6 ) Ethene can be polymerised to make (poly)ethene, used for carrier bags and drinks bottles because it strong and transparent. Propene can be polymerised to form (poly)propene, a strong and tough plastic used for carpets and rope. Smart polymers like shape memory polymers, change shape when they are hot or cold. Stitches that tighten due to the body’s temperature and then later dissolve are being developed. PET is the plastic used for drinks bottles because it is strong, light, waterproof and transparent. These properties mean it can be recycled for hiking jackets. Designer polymers are materials that chemists make with specific properties for a certain job. Light sensitive plasters cause less pain when removed. Cracking involves breaking down larger crude oil fractions into smaller more useful hydrocarbons.

___________involves breaking down larger crude oil fractions into _________ more _______ hydrocarbons. This reaction involves heating the crude oil fraction to a high ___________so that it ________. The vapour is then passed over a _________ or mixed with _____. Cracking is a _________ ________ reaction - ____ molecules are broken into _______ molecules using _______ Here is an example of cracking: 800°C + Catalyst C 10 H > C 5 H C 2 H 4 Decane _______ Propene ______ __________ can be used to test a compound to see if its an alkane or alkene. It stays _______ if a compound is ____________ It turns ____________ if a compound is ______________. Crude oil can be used to make plastics using a process called __________. This process involves joining together small molecules known as __________ into large molecules known as ___________. C1 Products from oil Polymerisation of ethene can represented like this: ___________ plastics are made partly using _________, which ___________ feed on to break it down. However, growing corn starch for ____and ______ could raise _________, destroy _______ and cause ______________. _________ is an ________. Ethanol for use in drinks is made by ___________of sugar using ______. sugar >ethanol + carbon dioxide The ethanol is produced in ______and gives off CO 2, a greenhouse gas. Ethanol for use as a fuel or a solvent can be made from ________and _______. This is a _________ reaction. It does not give off ___ and is a _________ process. However, ethene comes from _______ which means it is a _____________ production method. _______ are produced during cracking. These are __________ hydrocarbons which means they contain a ________ bond. Their general formula is _______ Ethene (C 2 H 4 ) Ethene can be polymerised to make ________________ used for carrier bags and drinks bottles because it _________ and ____________. Propene can be polymerised to form _____________ a strong and tough plastic used for _______ and ________. _______polymers like ________ _______polymers, change shape when they are hot or cold. Stitches that tighten due to the body’s ___________and then later ______ are being developed. PET is the plastic used for drinks bottles because it is ______, _______, _______ and _______. These properties mean it can be ________for hiking ______. _____________are materials that chemists make with specific properties for a certain job. _________plasters cause less pain when removed.