This is to help study for the NCEA Level 1, specialist science, carbon chemistry external. The criteria for the exam / what you'll be tested on is:    Structure of straight chain alkanes (up to 8 carbons), ethane and propene, methanol and ethanol.  This includes: Naming, using systematic nomenclature. Drawing structural formulae Describing covalent bonding between atoms within molecules. Physical properties of carbon compounds (as identified above), such as Solubility in water Trends in melting and/or boiling points and explanation of these trends Chemical reactions of carbon compounds such as Conditions and products of complete and incomplete combustion (including balanced equations) Reactions of ethene and propene to form polymers, including any conditions required for the reactions (eg; heat and catalysts). Production of carbon compounds by the following methods: Fractional distillation of crude oil Cracking of fractions Fermentation (including the conditions required and the chemical reaction occurring) Methanol from natural gas Uses and importance of fuels and polymers from ethene and propene. (Check out this BBC website about crude oil and oil products and its section on the formation of polymers.) Effects of combustion products on human health and the environment.  This may include: Effect on global climate Ocean acidification Air pollution  Use of non-renewable resources and food crops for fuels

Alkanes are hydrocarbons* that are fully saturated with hydrogen this means that they contain only single carbon-carbon covalent bonds. They are a homologous series.** Alkanes are classified according to the number of carbons on the longest straight part of their chain and will always end in -ane. The following are their prefixes: Meth - One carbon only Eth - Two carbons Prop - Three carbons But - Four carbons Pent - Five carbons Hex - six carbons Hept - seven carbons Oct - eight carbons  To remember the first four prefixes use - My Elephant Poops Bricks To name an Alkane first determine the number of carbons in the structure. Using the prefix for that number of carbons, put it in front of -ane (because it is an alkane the name will always end in -ane). For example, if a structure had five carbons, the prefix used would be Pent- and it would be written in front of -ane, like so: Pentane. This is the final name of the Alkane.  General formula: CnH2n+2 All bonding for alkanes are covalent and are only single covalent bonds. This also means that they are saturated.  Alkanes are primarily used as fuels (e.g. petrol)   When they burn, carbon dioxide and water are formed.     Methane + Oxygen -----> Carbon dioxide + water    CH4   + 2O2 -----> CO2 + 2H2O     *Hydrocarbons are organic compounds composed of only carbon and hydrogen atoms ** A series of compounds that have similar chemical properties and the same general formula

Alkenes are unsaturated hydrocarbons with hydrogen this means that they contain at least one double covalent bond and they are a homologous series.* Due to the double covalent bond in alkenes, two pairs of electrons are being shared between two carbon atoms. This means that these carbons do not contain the maximum number of hydrogen atoms. Therefore, alkenes are described as unsaturated.  The prefixes for alkenes are the same as the prefixes for alkanes because all hydrocarbons have the same prefixes. However the suffix for alkenes will always be -ene.  Alkenes can be produced from alkanes by cracking.  Mainly used in the manufacturing of plastics.                 * A series of compounds that have similar chemical properties and the same general formula

Molecular formula The molecular formula identifies the atoms within the molecule by their chemical symbol and indicates the number of atoms of each element using a subscript number. In the image above the molecular formula is seen along the bottom (CH4 and C2H6).  To write the molecular formula, a general formula is used. For alkanes the formula is CnH2n+2  (where n = to the number of carbon atoms). To get the molecular formula substitute the number of carbon atoms into the general formula and complete / solve.  Example: Pentane (five carbon)  General formula: CnH2n+2 Substitute the number of carbon atoms (five) in for 'n': C5H2*5+2 Solve / complete: C5H12 Final molecular formula: C5H12   Structural formula The structural formula is a graphic representation of the molecular structure and it shows how the atoms are arranged and bonded. In the image above the structural formula is seen above the molecular formula, structural formulas of alkanes were seen in the Naming Alkanes quiz.  To practise drawing the structural formula use the Carbon Chemistry, sciPAD and on page 14 there is a table to fill out where you can practise drawing the structural formula.