Question

19. what is a buffer?
a) a molecule that stores genetic information
b) a chemical that increases the acidity of a solution
c) a solution that resists changes in ph when acids or bases are added
d) a substance that speeds up chemical reactions
20. which functional group is found in alcohols?
a) amino group
b) carboxyl group
c) phosphate group
d) hydroxyl group
21. which functional group is characteristic of amino - acids?
a) phosphate group
b) amino group
c) carbonyl group
d) hydroxyl group

Explanation:

1. A buffer is defined as a solution that resists changes in pH when acids or bases are added. It contains a weak acid - conjugate base or weak base - conjugate acid pair.
2. Alcohols are characterized by the presence of the hydroxyl (-OH) functional group.
3. Amino acids have an amino group (-NH2) as one of their key functional groups.

Answer:

1. c) A solution that resists changes in pH when acids or bases are added
2. d) Hydroxyl group
3. b) Amino group