Chapters 20 & 21

1. Chapters 20 & 21 Carbon and Hydrocarbons & Other Organic Compounds

2. Sect. 20-2: Organic Compounds • Organic compound – covalently bonded compounds containing carbon (except carbonates and oxides) • Catenation – covalent binding of an element to itself to form chains or rings • Hydrocarbons – simplest organic compounds containing only carbon and hydrogen

3. Structural formula – indicates the number and types of atoms present in a molecule and also shows the bonding arrangement of the atoms • Condensed structural formula • Isomers – compounds that have the same molecular formula but different structures

4. 2 types of isomers • Structural isomers – isomers in which the atoms are bonded together in different orders • Example: butane and 2-methylpropane • Geometric isomers – isomers in which the order of atom bonding is the same, but the arrangement of atoms in space is different • Example: 1,2-dichloroethene

5. In order for geometric isomers to exist: • There must be a rigid structure to prevent free rotation around a bond • 2 carbons must have at least 2 different groups attached to them • Arrangements have different names, cis and trans • cis – same side of the molecule • trans – different side of the molecule

6. Sect. 20-3: Saturated Hydrocarbons • Saturated hydrocarbon – carbons form 4 single covalent bonds with other atoms • Alkane – hydrocarbon that contains only single bonds • Homologous series – a series in which adjacent members differ by a constant unit (in the case of alkanes it is 1 C and 2 H) • General formula is CnH2n+2

7. Cycloalkane – alkane in which the carbon atoms are arranged in a ring structure • Have 2 fewer hydrogens than the straight chain with the same number of carbons

8. Naming rules • For a straight-chain alkane, use a prefix telling how many carbons followed by –ane. • 1 – meth- 6 – hex- • 2 – eth- 7 – hept- • 3 – prop- 8 – oct- • 4 – but- 9 – non- • 5 – pent- 10 – dec- • Example a 5 carbon straight chain would be pentane

9. Alkyl groups are named by the same prefix as alkanes, but with –yl suffix • Alkyl group – groups of atoms that are formed when a hydrogen is removed from an alkane • Attached to “parent chain” to make a branched chain alkane • Names of alkyl groups are placed in front of the parent chain name and use prefixes (di, tri, tetra to tell how many of each alkyl group are attached)

10. If multiple alkyl groups exist, list in alpha order • Number the carbons of the parent chain in such a way that the alkyl groups are on the lowest # carbon • Include the number carbon that each alkyl group is attached to in the name • Separate numbers with commas and numbers from words with dashes

11. When naming a cycloalkane, use the same rules, except add the prefix cyclo- in front of the parent ring name

12. Sect. 20-4: Unsaturated Hydrocarbons • Unsaturated hydrocarbons – hydrocarbon in which some carbons have double or triple bonds • Alkene – hydrocarbon containing at least one double bond • General formula is CnH2n • Alkyne – hydrocarbon containing at least one triple bond • General formula is CnH2n-2

13. Rules for multiple bonds • All alkane naming rules apply for alkene and alkyne naming with a few exceptions/additions: • The parent chain is the longest carbon chain that contains the multiple bond • Instead of –ane suffix, use –ene for double bond and –yne for triple bond • If there is more than one double or triple bond, use di or tri just before the suffix to indicate how many double/triple bonds • Carbons should be numbered so that the multiple bond has the lowest number possible & the number of the carbon attached to the multiple bond is indicated just before the parent chain’s name (ex: 1-pentene)

14. Chapter 21Sect. 21-1&2: Functional Groups and Classes of Organic Compounds • Functional group – an atom or group of atoms that is responsible for the specific properties of an organic compound • Alcohols • Alkyl halides • Ethers • Aldehydes • Ketones • Carboxylic acids • Esters

15. Alcohol – organic compounds that contain one or more hydroxyl groups • Naming alcohols: • The parent chain must contain the hydroxyl group; # so it has lowest # • Replace the final –e in the name with –ol or if more than one hydroxyl group, use the whole name and then diol (2) or triol (3), etc. • Indicate which # carbon the hydroxyl group is attached

16. Alkyl halides – organic compounds in which one or more halogen atoms (F, Cl, Br, or I) are substituted for one or more hydrogen atoms • Naming alkyl halides: • Parent chain must include halide • Add prefix indicating which halide is attached and if necessary, add prefix to indicate how many • Indicate the # carbon to which the halide is attached • Ethers – organic compound in which two hydrocarbon groups are bonded to the same atom of oxygen • Naming ethers • The word ether will come at the end of the name • List the alkyl groups in alpha order in front of “ether” and use di if they are the same and put spaces between each word

17. Aldehyde – organic compound in which the carbonyl group is attached to a carbon atom at the end of a carbon chain • To name, change the end –e to -al • Ketone – organic compound in which the carbonyl group is attached to a carbon atom within the chain • To name, chage the end –e to –one and identify which carbon the ketone is attached to

18. Carboxylic acid – an organic compound that contains the carboxyl functional group • To name, change end –e to –oic acid; if more than one use dioic acid (2) or trioic acid (3), etc. • Ester – an organic compound with carboxylic acid group in which the hydrogen of the hydroxyl group has been replaced by an alkyl group • To name, name the carboxylic acid that it was formed from and then change the –oic acid to –oate • Name the alkyl group that replaced the hydrogen & add to front of name