1 Definition and formulae

Hydrocarbon is a compound consisting of hydrogen and carbon only Molecular formula: The formula which shows the actual number of each type of atom Saturated: Contain single carbon-carbon bonds only Unsaturated : Contains a C=C double bond General formula: algebraic formula for a homologous series e.g. CnH2n Empirical formula: shows the simplest whole number ratio of atoms of each element in the compound 3.1 Organic: Basic Concepts Basic definitions to know Displayed formula: show all the covalent bonds and atoms present in a molecule When drawing organic compounds add the hydrogen atoms so that H each carbon has 4 bonds C C C H H H H H H C C H H H H H Drawing Displayed formulae Remember that the shape around the carbon atom in saturated hydrocarbons is tetrahedral and the bond angle is 109.5o C C H H H H H H N Goalby chemrevise.org 1 Skeletal formula shows the simplified organic formula, shown by removing hydrogen atoms from alkyl chains, leaving just a carbon skeleton and associated functional Groups. Structural formula shows the minimal detail that shows the arrangement of atoms in a molecule, eg for butane: CH3CH2CH2CH3 or CH3 (CH2 )2CH3