Level 1. e.g. Alcohol Homologous Series. Anion. (advanced A level chemistry pre-university revision notes on functional groups and homologous series) 1st …AL e.g. e.g. In organic chemistry, a homologous series is a sequence of compounds with the same functional group and similar chemical properties in which the members of the series can be branched or unbranched, or differ by -CH2. Level 2 UNIT 2 Learn these words 40 ... the homologous series with the general formula CnH2n+2. This process is often called the Hofmann degradation and can be used to move down a homologous series. There are a number of homologous series in organic compounds. Such organic compounds that vary from one another by a repeating unit and have the same general formula form a series of compounds. The preparation of dyes from aromatic amines. Some important series of aliphatic compounds are listed below: If we examine the unbranched alkanes, we notice that each alkane differs from the preceding alkane by one —CH 2 — group. ethanal, propanal, or 2-methylpropanal. A homologous series in organic chemistry is a group of organic compounds (compounds that contain C atoms) that differ from each other by one methylene (CH 2) group. A negatively charged ion. Tutorials for Chemistry Learning !! Modern dyes are formed in a two-stage synthesis: the aromatic amine is converted into a diazonium salt Labels for atoms other than carbon are kept (see the nomenclature sections of other homologous series for examples of their skeletal formulae). The alcohols which only contain one hydroxyl group attached to a saturated carbon form a homologous series. A skeletal structure is similar to the displayed structure, though all the hydrogens are removed, including any bonds to hydrogen atoms, and the labels for carbon atoms are removed as well. Functional groups and homologous series Functional groups. butanal, pentanal, 2-methylbutanal. Carbon chains of varying length have been observed in organic compounds having the same general formula. Created by mclellann. This can be the length of a carbon chain, for example in the straight-chained alkanes (paraffins), or it could be the number of monomers in a homopolymer such as amylose. Aromatic amines, such as phenylamine, are important industrially for the production of dyes. AQA AS Level Chemistry Definitions. Exemplar homologous series - general formula for aliphatic aldehydes: ALDEHYDES have the -CHO functional group at the end of a carbon chain . A hydrocarbon homologous series is a series of hydrocarbons which: Have the same general formula; Differ by CH 2 in molecular formulae from neighbouring compounds When an atom or group of atoms bonded to a carbon atom in the chain or ring of an organic compound, shown some characteristic properties of their own, they are termed as a functional group. Homologous series is a series of compounds with similar chemical properties and some functional group differing from the successive member by CH 2. Atom economy (Total Mr of useful products/Total Mr of reactants) x 100. average bond enthalpy .