Chapter 9

Question 1

amino acid

Answer 1

One of 20 building blocks of proteins.

Question 2

amphiprotic

Answer 2

A molecule that can act as both a proton donor and a proton acceptor. The intermediate species of polyprotic acids are amphiprotic.

Question 3

diprotic acids and bases

Answer 3

Compounds that can donate or accept two protons.

Question 4

hydrolysis

Answer 4

“Reaction with water.”

Question 5

isoelectric focusing

Answer 5

A technique in which a sample containing polyprotic molecules is subjected to a strong electric field in a medium with a pH gradient. Each species migrates until it reaches the region of its isoelectric pH. In that region, the molecule has no net charge, ceases to migrate, and remains focused in a narrow band.

Question 6

isoelectric point

Answer 6

The pH at which the average charge of a polyprotic species is 0. Same as isoelectric pH.

Question 7

isoionic point

Answer 7

The pH of a pure solution of a neutral, polyprotic molecule. The only ions present are H+, OH-, and those derived from the polyprotic species. Same as isoionic pH.

Question 8

polyprotic acids and bases

Answer 8

Compound that can donate or accept more than one proton.

Question 9

speciation

Answer 9

Describes the distribution of an element or compound among different chemical forms.

Question 10

zwitterion

Answer 10

A molecule with a positive charge localized at one position and a negative charge localized at another position.