AQA A Level Chemistry Year 1- Alkenes Revision Questions and Answers

What is an alkene? An unsaturated hydrocarbon What is an unsaturated hydrocarbon? A compound containing only carbon and hydrogen atoms and containing at least one carbon carbon double bond What are van der Waals forces? Relatively weak intermolecular forces caused by temporary dipole dipole interaction What is the general formula for an alkene? CnH2n How would you name an alkene given its displayed formula? Identify the longest carbon chain Identify the position of the carbon carbon double bond Identify any side chains What are structural isomers? Molecules with the same molecular formula, but with different a structural formula What are stereoisomers? Molecules with the same molecular AND structural formula but a different 3D arrangement of their atoms in space What is E-Z isomerism? The highest priority groups are on the same side of the double bond Describe the C=C double bond Double covalent bond Planar bond Area of high electron density How do you assign the highest priority of groups in E-Z isomerism? The highest atomic number closest to the double bond has the highest priority If two groups have e.g. Only carbon and hydrogen, then the one with the most carbon atoms is assigned the highest priority What are Z isomers? Molecules where the highest priority groups are on the same side What are E isomers? Molecules where the highest priority groups are on opposite sides