Loading in 2 Seconds...
Loading in 2 Seconds...
Chpt. 22: Some Families of Organic Compounds (Organic Chemistry). 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.
Chpt. 22: Some Families of Organic Compounds (Organic Chemistry)
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
All ten of these families can be split into two groups: Group 1 – Tetrahedral *Do Not Take Diagram
Group 2 – Planar *Do Not Take Diagram
Group 1: Tetrahedral • Alkanes • Chloroalkanes • Alcohols Group 2: Planar • Alkenes • Alkynes • Aldehydes • Ketones • Carboxylic Acids • Esters • Aromatic Conpounds
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CHLOROALKANES: Chloroalkanes are compounds in which one or more of the hydrogen atoms in an alkane molecule have been replaced by a chlorine atom The part of an alkane remaining after one hydrogen is removed is an alkyl group e.g. Methane CH4minus a hydrogen group leaves methyl -CH3
Remember: Alkyl Radicals *Do Not Take This Slide
Chloroalkanes are named after the alkane from which they are derived with the prefix chloro- indicating the presence of chlorine.
*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)
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
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
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.
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
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
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