Exam 2 - Properties of Solutions

Question 1

—Most drugs are:

A.Strong electrolytes

B.Weak electrolytes

C.Nonelectrolytes

D.None of the above

Answer 1

B.Weak electrolytes

Question 2

—Mixing substances with similar properties forms ideal solutions.

—When 100 mL of methanol is mixed with 100 mL of ethanol, the final volume of the solution is 170 mL/200 mL

A.Ideal solution; 170 mL

B.Real solution; 170 mL

C.Ideal solution; 200 mL

D.Real solution; 200 mL

E.None of the above

Answer 2

C.Ideal solution; 200 mL

Question 3

—H2O can act as a(n):

A.Acid only

B.Base only

C.Acid or base

D.None of the above

Answer 3

C.Acid or base

Question 4

—Salts of weak acids or weak bases are:

A.Completely ionized in solution

B.Partially ionized in solution

C.There is no rule of thumb regarding their ionization

Answer 4

A.Completely ionized in solution

Question 5

—Strong electrolytes are completely ionized in dilute solutions.

—Strong electrolytes include:

—A.Strong acids

B.Strong bases

C.All salts

D.A and B

E.A, B and C

Answer 5

E.A, B and C

Question 6

—Which statement is true?

A.There are no drugs that are more active when in the ionic state

B.Some drugs are more active when in the ionic state

C.All drugs are more active when in the ionic state

Answer 6

B.Some drugs are more active when in the ionic state

Question 7

—In general, the ionized forms are:

—A.More water-soluble but much less soluble in lipid

B.More lipid-soluble but much less soluble in water

C.There is no rule of thumb that connects ionization to solubility in water or lipids

Answer 7

—A.More water-soluble but much less soluble in lipid

Question 8

—If an acid or base is added to water, the pH of the latter is changed:

—A.Slightly

B.Markedly

Answer 8

B.Markedly

Question 9

“In a general way, the concentration of acid in a weak-acid/conjugate-base buffer determines the capacity to neutralize added base”. This statement is:

A.True

B.False

Answer 9

A.True

Question 10

—A characteristic of buffered solutions is that they undergo ____________ of pH upon addition of acid or base:

—A.No changes

B.Small changes

C.Substantial changes

Answer 10

B.Small changes

Question 11

—For both weak acids and bases, the amount of drug that is ionized if the pH of the solution is equal to the drug’s pKa is:

—A.0%

B.25%

C.50%

D.75%

E.100%

Answer 11

C.50%

Question 12

Henderson-Hasselbach equation may be used to calculate:

A.The approximate values of pH of buffer solutions

B.The ratio of molar concentrations of a buffer system required to produce a solution of specific pH

C.The pKa of an acid or base

D.A and C only are correct

E.A, B and C are correct

Answer 12

E.A, B and C are correct

Question 13

—Buffered solution A consists of 0.01 M acetic acid and 0.01 M sodium acetate; Buffered solution B consists of 0.05 M acetic acid and 0.05 M sodium acetate; Will the 2 solutions have the same pH?

—A.Yes

B.No

Answer 13

—A.Yes

Question 14

—“When the buffer is equimolar in the concentrations of weak acid and conjugate base, or of weak base and conjugate acid, it has equal buffer capacity toward added strong acid or strong base”. This statement is:

—A.True

B.False

Answer 14

A.True