An alkyl group is formed by removing one hydrogen from the alkane chain and is described by the formula C n H 2n+1. The removal of this hydrogen results in a stem change from -ane to -yl. Die allgemeine Formel der Alkane lautet C n H 2n+2 mit n = Anzahl der Kohlenstoffatome. We begin our study of organic chemistry with the hydrocarbons, the simplest organic compounds, which are composed of carbon and hydrogen atoms only. Take a look at the following examples. Although there is only one alkene with the formula C 2 H 4 (ethene) and only one with the formula C 3 H 6 (propene), there are several alkenes with the formula C 4 H 8. Alkanes can be described by the general formula C n H 2n+2. The list of some Alkanes and the molecular formula is given below.Methane (CH4), Ethane (C2H6), Propane (C3H8), Butane (C4H10), Pentane (C5H12), Hexane (C6H14), Heptane (C7H16), Octane (C8H18), Nonane (C9H20), Decane (C10H22). The simplest alkane, methane, has one carbon atom and a molecular formula of CH 4. This group of compounds comprises a homologous series with a general molecular formula of C n H 2 n+2, where equals any integer. The alkanes comprise a series of compounds that are composed of carbon and hydrogen atoms with single covalent bonds. Unbranched, saturated hydrocarbon chains are named systematically with a Greek numerical prefix denoting the number of carbons and the suffix "-ane". The IUPAC nomenclature (systematic way of naming compounds) for alkanes is based on identifying hydrocarbon chains. Here are some basic rules for naming alkenes from the International Union of Pure and Applied Chemistry (IUPAC): As we noted, there are several different kinds of hydrocarbons. To identify and name simple (straight-chain) alkanes given formulas and write formulas for straight-chain alkanes given their names.