2Functional groupsFunctional groups are parts of molecules that result in characteristic features.Many functional groups exist, we will focus on about 4.
3Organic compounds having functional groups AlcoholsCarboxylic acidsAmino acidscarbohydrates
41. Alcoholsa class of organic compounds with an –OH (hydroxyl ) functional group.thus R-OH is the formula (The symbol “R” is used to represent any carbon chains or rings).
5Alcohols CH4O C2H6O condensed structural IUPAC common formula formula name nameCH4OH – C – O – HHMethyl alcoholmethanolH – C – C - O – HHC2H6OethanolEthyl alcohol
6Alcohols C2H6O2 C3H8O3 condensed structural IUPAC common formula formula name nameHHC2H6O2Ethylene glycolH – C – C – HOHethanediolH – C – C - C – HHOHC3H8O3propanetriolglycerol
7Naming alcohols For IUPAC: drop the -e ending of the parent alkane name; add the ending -ol.Ethane ethanolH – C – C - O – HH
8Naming alcoholsAlcohols containing 2, 3, and 4 of the -- OH groups are named diols, triols, and tetrols respectively.H – C – C - C – HHOHpropanetriol
9Naming alcohols Common names: name the alkyl group, then followed by the word alcohol.One carbon alcohol = methyl alcoholH – C – O – HH
10Properties of alcohols Much like water, alcohols are capable of forming hydrogen bonding between molecules. This meansthey will boil at a higher temp. than alkanes with a comparable number of C atoms.Alcohols of up to 4 carbons are soluble in water in all proportions.
112. Carboxylic acids General formula: R-COOH - C – OHOFunctional group: - COOH or(carboxyl group)General formula: R-COOHweak acids (ionize slightly)
12Carboxylic acidsNamed by replacing the -e ending of the corresponding alkane name with -oic and followed by the word acidmethanoic acid; ethanoic acid.
13Carboxylic acids CH2O2 C2H4O2 condensed structural IUPAC common formula formula name nameOmethanoic acidFormic acidCH2O2H - C – OHH – C -C – OHOHC2H4O2Acetic acidEthanoic acid
143. Amino acids Functional groups: - NH2 (amino) and O (carboxyl). - C – OHO(carboxyl).
15Amino acids C2H5NO2 C3H7NO2 condensed structural common formula formula nameH2N - C - C – OHOHglycineC2H5NO2H2N - C - C – OHOHCH3alanineC3H7NO2
164. Carbohydrates O The functional group is (carbonyl) - C – O or -C – HO(aldehyde).
17Carbohydrates H – C = O H – C – O H H – C – OH C = O HO – C – H fructoseGlucose, C6H12O6
18Hydrophilic groups Hydrophilic means “water loving.” Hydrophilic groups are electrically polarized. This makes the substances including a hydrophilic group soluble in polar solvents like water.Examples: - OH, - COOH, - NH2
19Hydrophobic groupsHydrophobic means “water hating.” Hydrophobic groups are not electrically polarized. Therefore, hydrophobic substances are not soluble in water but soluble in non-polar solvents like benzene.Examples: alkanes, ethylene, acetylene, CCl4, oils, and fats.
20Hydrophilic and hydrophobic groups The common soap is the Na salt of stearic acid. Its formula is: CH3(CH2)16COONa.When it dissolves in water, it produces Na+ and CH3(CH2)16COO- ions.CH3(CH2)16 COO-Hydrophobic tailHydrophilic head
21Hydrophilic and hydrophobic groups oiloilMicelleHydrophobic tails dissolve oil. Hydrophilic heads stay away from oil but attracted by water molecules. So, the oil is washed away by soap and water.