1. ORGANIC CHEMISTRY The chemistry of compounds that contain both carbon and hydrogen

2. Before we start, let’s get one thing straight… THE SYMBOL FOR CARBON IS “C” NOT “Ca” !!!

3. Carbon (C) There are more than a million organic compounds There are more than a million organic compounds More than 95% of the compounds from natural sources or synthesized in the laboratory are organic More than 95% of the compounds from natural sources or synthesized in the laboratory are organic The simplest organic compounds contain only carbon and hydrogen and are called hydrocarbons (HC) The simplest organic compounds contain only carbon and hydrogen and are called hydrocarbons (HC) In other organic molecules, Carbon can bond with many other atoms, such as Oxygen, Nitrogen, Fluorine, Bromine, Sulfur, Phosphorus and Chlorine In other organic molecules, Carbon can bond with many other atoms, such as Oxygen, Nitrogen, Fluorine, Bromine, Sulfur, Phosphorus and Chlorine One Carbon can form 4 covalent bonds One Carbon can form 4 covalent bonds

4. Hydrocarbons Made up of only Hydrogen and Carbon oIn these molecules, Carbon will bond with either Hydrogen or another Carbon oHydrogen can only form ONE bond oCarbon will form FOUR bonds oThe two simplest Hydrocarbons (HC) are methane and ethane oNonpolar molecules (charge and electrons are evenly distributed) oBecause of this, hydrocarbons tend to be gases or liquids

5. (a) Methane: CH 4 + → o Major form of natural gas o Formed by bacterial decay of dead organic matter o Livestock and termites emit large amounts o Carbon has four valence electrons and so it ALWAYS forms four covalent bonds o Not a typical HC as there is no carbon-carbon bond

6. (b) Ethane: C 2 H 6 oCarbon-carbon single bond (shared pair of electrons) oSix single bonds with six hydrogen atoms oA gas at STP

7. (c) HC Formulas and Models oMolecular formulas: e.g. oStructural formulas e.g. oBall-and-stick models e.g. oSpace-filling models e.g. CH 4

8. 2. Alkanes oMethane and Ethance are examples of alkanes oA HC with all single covalent bonds oThe carbon atoms can be arranged in a straight chain (bends don’t matter) or branched chain

9. (a) Straight Chain Alkanes oEthane is the simplest alkane oStraight chain of any number of carbon atoms oThese compounds form a homologous series, having the same formula: C n H 2n+2 oThe boiling point of alkanes increase as the number of carbon atoms increases (reflects increase in molar mass) Propane used in air balloons

10. (b) Naming Straight- Chained Alkanes oEnd with the suffix – ane oThe Latin prefix indicates the number of carbons oMolecular Formula: C n H 2n+2 #C#C Name Molecular Formula 1 Methane CH 4 2 Ethane C2H6 C2H6 3 Propane C3H8 C3H8 4 Butane C 4 H 10 5 Pentane C 5 H 12 6 Hexane C 6 H 14 7 Heptane C 7 H 16 8 Octane C 8 H 18 9 Nonane C 9 H 20 10 Decane C 10 H 22

11. (c) Formulas for Alkanes = Some bonds or atoms are left out

12. (d) Branched-Chain Alkanes oAn atom or group of atoms that take the place of an H atom is called a substituent oThe longest continuous carbon chain is the parent alkane oSubstituents can include halogens, oxygen, nitrogen, sulfur, and phosphorus oIf the substituent is another hydrocarbon (only H and C atoms), it is called an alkyl group

13. (e) Naming Branched-Chain Alkane oName the longest chain of carbons (bends don’t matter) oCircle all branches oNumber the carbons, so that branches have lowest numbers possible oName each substituent using its number, the prefixes, and the adding the ending “-yl” oList the substituents in alphabetical order oIf you have more than 1 of the same branch, add “di”, “tri”, “tetra”, or “penta” to the name of the branch oWrite the full name starting with branches, and ending with the parent chain

14. Structural Isomers Some hydrocarbons differ only in the positions of their alkyl groups Some hydrocarbons differ only in the positions of their alkyl groups They have the same molecular formula, but different structures (atoms are joined in a different order) They have the same molecular formula, but different structures (atoms are joined in a different order) They are called structural isomers They are called structural isomers Structural isomers have different physical and chemical properties Structural isomers have different physical and chemical properties

15. Structural Isomers of C 4 H 10 Butane 2-methylpropane Notice how both have 4 carbons and 10 hydrogens, but one is branched, and one is a straight-chain alkane