Hydrocarbons

• Organic compounds contain carbon.
• Hydrocarbons are compounds which contain exclusively carbon and hydrogen. They can be classed as either saturated or unsaturated.
• A hydrocarbon is saturated if it contains as much hydrogen as possible. If a hydrocarbon has fewer hydrogen atoms than the maximum, then we class it as unsaturated.
• Saturated hydrocarbons only contain single bonds between carbon atoms. This means that the carbon atoms can bond to more hydrogen atoms since there is no double bond.
• Unsaturated hydrocarbons are compounds which contain one or more covalent bonds (multiple bonds).
• Multiple bonds are two or more covalent bonds between atoms. These include double and triple.
• Nomenclature refers to the set of rules which outlines how organic compounds should be named and represented.
• Organic compounds can be represented in many different ways. These include displayed formula, structural formula, skeletal formula, molecular formula, empirical formula and general formula.
• Displayed formula is a formula that shows every atom and bond in a compound.
• Structural formula shows how atoms in a compound are joined together.
• Skeletal formula shows all the bonds between carbon atoms in a compound. Every end of a line corresponds to a carbon atom.
• Molecular formula shows the actual numbers of each atom in the molecule. However, it doesn't show the structure.
• Empirical formula shows the numbers of each atom in the simplest whole number ratio. It is written similarly to the molecular formula.
• General formula shows a general rule followed by all members of a homologous series.
• A functional group is an atom or group of atoms that gives a compound some distinctive and predictable properties. For example, the functional group of a carboxylic acid is -COOH.
• A homologous series is a set of compounds with the same functional group, similar chemical properties and physical properties that show a gradation between each one (gradual change).
• Alkanes are the main compounds used as fuels.
• Alkanes have the general formula CnH2n+2.
• Alkenes have the general formula CnH2n.
• Halogenoalkanes have the general formula CnH2n+1X. X refers to the halogen that the halogenoalkane contains.
• Alcohols have the general formula CnH2n+1OH.
• The homologous series of alkanes can be used to illustrate similarities of properties in a series. For example, when alkanes are burned, they all produce carbon dioxide and water.
• The homologous series of alcohols can be used to illustrate the gradation in physical properties of a homologous series. This trend shows that as the number of carbon and hydrogen atoms increases, so does the boiling point.