1. or functional groups

2. Functional groups
Functional groups are parts of molecules that result in characteristic features.
Many functional groups exist, we will focus on about 4.

3. Organic compounds having functional groups
Alcohols
Carboxylic acids
Amino acids
carbohydrates

4. 1. Alcohols
a 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).

5. Alcohols CH4O C2H6O condensed structural IUPAC common
formula formula name name
CH4O
H – C – O – H H
Methyl alcohol
methanol
H – C – C - O – H H
C2H6O
ethanol
Ethyl alcohol

6. Alcohols C2H6O2 C3H8O3 condensed structural IUPAC common
formula formula name name H H
C2H6O2
Ethylene glycol
H – C – C – H OH
ethanediol
H – C – C - C – H H OH
C3H8O3
propanetriol
glycerol

7. Naming alcohols For IUPAC:
drop the -e ending of the parent alkane name; add the ending -ol.
Ethane ethanol
H – C – C - O – H H

8. Naming alcohols
Alcohols containing 2, 3, and 4 of the -- OH groups are named diols, triols, and tetrols respectively.
H – C – C - C – H H OH
propanetriol

9. Naming alcohols Common names:
name the alkyl group, then followed by the word alcohol.
One carbon alcohol = methyl alcohol
H – C – O – H H

10. Properties of alcohols
Much like water, alcohols are capable of forming hydrogen bonding between molecules. This means
they 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.

11. 2. Carboxylic acids General formula: R-COOH
- C – OH O
Functional group: - COOH or
(carboxyl group)
General formula: R-COOH
weak acids (ionize slightly)

12. Carboxylic acids
Named by replacing the -e ending of the corresponding alkane name with -oic and followed by the word acid
methanoic acid; ethanoic acid.

13. Carboxylic acids CH2O2 C2H4O2 condensed structural IUPAC common
formula formula name name O
methanoic acid
Formic acid
CH2O2
H - C – OH
H – C -C – OH O H
C2H4O2
Acetic acid
Ethanoic acid

14. 3. Amino acids Functional groups: - NH2 (amino) and O (carboxyl).
- C – OH O
(carboxyl).

15. Amino acids C2H5NO2 C3H7NO2 condensed structural common
formula formula name
H2N - C - C – OH O H
glycine
C2H5NO2
H2N - C - C – OH O H
CH3
alanine
C3H7NO2

16. 4. Carbohydrates O The functional group is (carbonyl) - C – O or
-C – H O
(aldehyde).

17. Carbohydrates H – C = O H – C – O H H – C – OH C = O HO – C – H
fructose
Glucose, C6H12O6

18. Hydrophilic 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

19. Hydrophobic groups
Hydrophobic 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.

20. Hydrophilic 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 tail
Hydrophilic head

21. Hydrophilic and hydrophobic groups
oil
oil
Micelle
Hydrophobic tails dissolve oil. Hydrophilic heads stay away from oil but attracted by water molecules. So, the oil is washed away by soap and water.

22. Micelle
oil

23. References