Alkenes and Alcohols 0.0 / 5 ? ChemistryAlkenes and AlcoholsASAQA Created by: Maisie_Jane711Created on: 26-06-17 15:22 E/Z isomerism Same molecular formula but different structurl formula. Restricted roatation around planar double bond. Stereoisomers = same molecular and structural formula, but different three-dimensional arrangment in space. Z = On the same side. E = On the oppisite side. Groups are ranked using CIP priority, atomic number used for this. 1 of 7 Addition polymers Polymers are named from the alkenes in which they were formed from e.g (poly(ethene), poly(pentene)). Addition polymers are unreactive and so are used widespread as inert materials. High density poly(ethene) is used for kitchen ware and low density poly(ethene) is used for plastic bags. Strong covalent bonds within polymers and weak van der waals between polymers. Having fewer branches = stronger VDW forces, stronger and harder material More branches = weaker VDW forces, weaker and softer materials. Longer the chain = stonger VDW forces/higher melting point. 2 of 7 Reactions of Alkenes C=C bond = high electron density, so susceptable to electrophiles. Electrophiles = a substance which can accept a pair of electrons, polar molecules. Addition reaction = two molecules join together to make one larger molecule 3 of 7 Production of ethanol from ethene Hydration = adding water to a substance. Catalyst = concentrated phosphuric acid. Mixture is kept at 60atm and 600K to ensure 100% yield. Side reactions can reduce the yield. 4 of 7 Physical properties of alcohols Greater boiling point than alkenes, similar relative molecular mass due to the presence of hydrogen bonding between molecules. Short chain alcohols are soluble in water, alkanes are not. Primary alcohols = 1 R group, Secondary = 2 R groups, Tertiary = 3 R groups. 5 of 7 Reactions of Alcohols Oxidation: Primary alcohols are easily oxidised to produce aldehydes. Secondary oxidised to produce ketones and Tertiary = not easily oxidised. Elimination: Where one small molecule is removed from a reactant molecule. A molecule of water can be removed to produce an alkene. Can also be described as a dehydration reaction, where a molecule of water is eliminated. 6 of 7 Production of ethanol Fermentation: When yeast and bacteria turn sugars into alcohols. Turns glucose into ethanol and CO2. Hydration of ethene: Ethene + steam <--> ethanol. 7 of 7
Basic concepts and hydrocarbons, Alcohols, Halogenoalkanes and analysis, Energy 1.0 / 5 based on 2 ratings
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