Chpt. 22: Some Families of Organic Compounds (Organic Chemistry)

1. Chpt. 22: Some Families of Organic Compounds (Organic Chemistry)

2. Previously studied organic families: Alkanes Alkenes Alkynes Aromatic Compounds This section involves the study of further organic families: Chloroalkanes Alcohols Aldehydes Ketones Carboxylic Acids Esters

3. All ten of these families can be split into two groups: Group 1 – Tetrahedral *Do Not Take Diagram

4. Group 2 – Planar *Do Not Take Diagram

5. Group 1: Tetrahedral • Alkanes • Chloroalkanes • Alcohols Group 2: Planar • Alkenes • Alkynes • Aldehydes • Ketones • Carboxylic Acids • Esters • Aromatic Conpounds

6. Tetrahedral Carbon Compounds In saturated organic compounds, ALL of the carbon atoms are tetrahedral CHLOROALKANES: Chloroalkanes are compounds in which one or more of the hydrogen atoms in an alkane molecule have been replaced by a chlorine atom The part of an alkane remaining after one hydrogen is removed is an alkyl group e.g. Methane CH4minus a hydrogen group leaves methyl -CH3

7. Remember: Alkyl Radicals *Do Not Take This Slide

8. Chloroalkanes are named after the alkane from which they are derived with the prefix chloro- indicating the presence of chlorine.

9. Chloroalkanes of METHANE

10. *Important Note* You must be able to name and draw the structure of all the chloroalkanes for the first four alkanes!!! (methane, ethane, propane, butane)

11. Naming and Drawing structural formulas of Chloroalkanes: • 1. Draw full structural formula of compound • 2. Identify longest continous chain of carbon atoms - • parent alkane • 3. Number carbon atoms from the end that gives lowest • number to the carbon atom to which the • chlorine atom is attached • 4. Indicate position of chlorine atom e.g 2-chloro- • 5. Name compound

12. Example: Name the compounds: a) CH3CH2CHClCH3 b) CH3CCl2CHClCH3 c) CH3CCl(CH3)CH3 Student Questions: Workbook – pg 60 W22.1, W22.2, W22.3 Homework: Book – pg 360 22.1,22.2, 22.3

13. Physical State and Properties of Chloroalkanes • Chloroalkanes are slightly polar • Chloroalkanes are insoluble in water but are soluble • in non-polar solvents e.g. cyclohexane, • methylbenzene • Chloroalkanes have low boiling points but because • of the polarity of the carbon/chlorine bond • chloroalkanes have higher boiling points than • corresponding alkanes. • *Note: Boiling point depends on the strength of the • intermolecular forces, so, because longer carbon • chains have stronger van der Waals forces between • molecules they will have higher boiling points.

14. Most chloroalkanes liquid at room temperature, • exception – chloromethane* and chloroethane are • gaseous • Main use is as solvents: • - for removing oil and grease machinery, dry cleaning • - paint stripper (dichloromethane) • - Tippex* • *Ozone Layer

15. Functional Group (Active Group) A functional group is an atom or group of atoms that defines the particular chemistry of a homologous series. Homologous Series Functional Group Alkanes C-C single bond Alkenes C=C double bond Alkynes C=C triple bond

16. ALCOHOLS

17. Alcohols form a homologous series of compounds of formula: • CnH2n + 1OH • Functional group – OH group (V-shaped) called • hydroxyl group • AlcOHol • Alcohols are formed when the hydrogen atom in • an alkane is replaced by the hydroxyl group (OH) • Carbon atoms including that joined to the OH • group are *TETRAHEDRAL* • Named by replacing -ane at end of corresponding • alkane with -ol

18. Primary, Secondary Tertiary Alcohols