Functional Group Atom or group of atoms that replaces a hydrogen atom in a hydrocarbon. Functional groups give the molecule personality.
Functional Group Each functional group gives the molecule distinctive chemical & physical properties. Molecules with functional groups contain at least one atom that is not C or H. Not hydrocarbons!
Names of molecules with functional group Derived from the name of the hydrocarbon with the same number of carbon atoms.
Halides or halocarbons or alkyl halides One or more H in an alkane is replaced with a halogen (F, Cl, Br, or I). General formula = R-X. X is the halogen. R is the alkyl branch.
Properties of Halides Likely to be polar molecules, unless very symmetric. Dipole-dipole interactions.
Polar Molecules Have POLES. The electron cloud is lop-sided. One end of molecule is electron-rich & the other electron-poor. Dipole-dipole interactions.
Polar Molecules Atoms in molecule have very different electronegativities. Molecule is not symmetrically shaped.
Properties of Halides Higher mp, bp, Hf, Hv than the corresponding alkanes. Lower rate of evaporation & vapor pressure than the corresponding alkanes.
Alcohols One or more hydrogens in a hydrocarbon replaced with an OH group. General formula = R-OH. The OH or hydroxyl group does NOT ionize in water.
Properties of Alcohols NONelectrolytes. No H+ or OH- ions in solution. Do NOT turn litmus red, etc.
Properties of Alcohols Contain O-H bond. Molecules tend to be polar. Dissolve in water. Hydrogen bonding takes place between alcohol molecules. Higher mp, bp than corresponding alkanes.
Naming Alcohols Replace final –e of corresponding alkane name with –ol.
Classification of alcohols by number of -OH groups. Monohydroxy: 1 -OH group. Dihydroxy: 2 –OH groups. Trihydroxy: 3 -OH groups.
Further classification of monohydroxy alcohols by carbon to which OH group attached. Primary: OH group at end carbon. Secondary: OH group on middle carbon. Tertiary: OH group at branch-point carbon.
Ethers Contain an O atom bridge connecting 2 alkyl branches. General Formula: ROR‘ R & R‘ are alkyl groups (the 2 branches). R & R‘ can be same or different.
Properties of Ethers Tend to be nonpolar.
Naming Ethers Name branches alphabetically. Stick the word “ether” at the end.
Carbonyl Group O C in a chain that has a double bond to an O. >C=O or C
Aldehydes Contain a carbonyl group at the end of the chain.
Naming Aldehydes Replace final “e” of corresponding alkane name with “al.”
Ketones Contain a carbonyl group on a carbon atom inside the chain, not at the end.
Naming Ketones Replace final “e” of corresponding alkane name with “one.”
Properties of ketones Carbonyl group is quite polar. Tend to be soluble in both polar & nonpolar solvents.
Organic Acids O Contain a –COOH group at the end of the molecule. -C-O-H
Organic Acids O The H in the –COOH group is acidic! -C-O-H
Properties of organic acids O Turn litmus red. Electrolytes! -C-O-H
Naming organic acids Replace the final –e of the corresponding alkane name with “-oic acid”
Esters Contain 2 oxygens! Bridge O in the middle of the chain. Carbonyl O right next door.
General formula of esters Bridge O Carbonyl O O R-CO-OR‘ R-C-O-R'
Naming Esters Name alkyl branch next to bridge O. Name branch with carbonyl group. Replace –e of corresponding alkane name with -oate.
Formation of Esters Format of esterification rxn: Alcohol + Org. Acid Ester + H2O
H O H H H Formation of Esters H H H H O H H H H HCCOCCCH + H2O HCCOH + HOCCCH H H H H
Amines Replace H in an alkane with –NH2 group. Replace final –e in alkane name with amine. # gives location of NH2 group. Analogous to alcohols
Properties of Amines Tend to smell really bad. Contain N-H bond. Exhibit H-bonding between molecules.
Amides O Contain NH2 group bonded to a carbonyl group. General formula: R-C-NH2
Naming Amides Find name of corresponding alkane. Drop final -e & add –amide. Never need a # - Always at the end.
Amino Acids Contain COOH group at end. C right next door has NH2 or amino group.
Polymer Large molecules made of chains of smaller units covalently bonded together.
Monomer Each individual unit of a polymer
Polymerization Reaction leading to formation of polymers