Chemistry A-Level (AQA) : 3.1 (Introduction to organic chemistry) 100% pass

What is empirical formula? Simplest whole number ratio of atoms of each element in a compound What is molecular formula? Actual number of atoms of each element in a compound. What is general formula? Algebraic formula for a homologous series What is structural formula? Shows the unique arrangement of atoms in a molecule in a simplified form, without showing all the bonds. Each carbon is written separately, with the atoms or groups that are attached to it. Branches in the carbon chains are shown in brackets. What is displayed formula? Shows every atom and every bond in the molecule What is skeletal formula? Shows the bonds of the carbon skeleton only, with any functional groups. Straight lines represent carbon-carbon bonds and carbon atoms are assumed to be where the bonds meet. The hydrogen and carbon atoms are not shown. What is homologous series? A family of organic compounds with the same functional group, but different carbon chain length What is functional group? An atom or groups of atoms, which when present in different molecules cause them to have similar chemical properties IUPAC rules for nomenclature ... The characteristics of a homologous series Members of a homologous series contain the same functional group and have similar chemical properties. Members of a homologous series have the same general formula. Members of a homologous series show a gradual change in physical properties. Mechanisms: free-radical The unpaired electron in a radical is represented by a dot Mechanisms : formation of a covalent bond A curly arrow that starts from a lone electron pair or from another covalent bond Mechanisms : breaking of a covalent bond A curly arrow starting from the bond What is isomerism? Isomers are molecules that have the same molecular formula but whose atoms are arranged differently What is structural isomerism? Structural isomers have the same molecular formula but different structural formulae Structural isomerism: chain isomerism The hydrocarbon chain is arranged differently such as branching Structural isomerism: functional group isomerism There are different functional groups Structural isomerism: positional isomerism The functional group is at different points of the hydrocarbon chain What is stereoisomerism? Compounds have the same structural formula and they differ in the arrangement of the bonds in space What is E-Z isomerism? A form of stereoisomerism and occurs as a result of restricted rotation about the planar carbon-carbon double bond.