Tutorial 7

Question 1

pH of blood plasma

Answer 1

7.4

Question 2

pH of saliva

Answer 2

6.4-7.1

Question 3

sweat

Answer 3

4.00-6.8

Question 4

tears

Answer 4

7.2-7.4

Question 5

urine

Answer 5

4.8-7.5

Question 6

gastric juice

Answer 6

1.4-2

Question 7

intestinal juice

Answer 7

6.3-8.0

Question 8

pancreatic juice

Answer 8

7.5-8.8

Question 9

interstitial fluid

Answer 9

6.3-8.0

Question 10

intracellular fluid

Answer 10

6.0-7.2

Question 11

cerebrospinal fluod

Answer 11

7.2-7.5

Question 12

skin

Answer 12

6.2-7.5

Question 13

The resistance to change in pH is known as ______ or ______

Answer 13

buffer action, buffer capacity

Question 14

What is the pH of blood plasma?
• A) 7.4
• B) 6.8
• C) 4.0
• D) 7.2

Answer 14

A

Question 15

Which of the following fluids has the lowest pH?
• A) Saliva
• B) Sweat
• C) Gastric juice
• D) Tears

Answer 15

C

Question 16

What is the main role of buffers in pharmaceutical solutions?
• A) To change color
• B) To resist changes in pH
• C) To resist changes in taste
• D) To increase drug bioavailability

Answer 16

B

Question 17

Which of the following buffers is made of citric acid and sodium citrate?
• A) Phosphate buffer
• B) Citrate buffer
• C) Acetate buffer
• D) Bicarbonate buffer

Answer 17

B

Question 18

Which of the following is a weak acid/its salt buffer?
• A) Acetic acid and sodium acetate
• B) Sodium chloride and water
• C) Hydrochloric acid and sodium chloride
• D) Ammonia and ammonium chloride

Answer 18

A

Question 19

What is the buffer capacity?
• A) The ability of a buffer to change pH
• B) The resistance to change in pH
• C) The ability to increase the solubility of a drug
• D) The resistance to oxidation

Answer 19

B

Question 20

Which of the following pharmaceutical products need pH adjustment?
• A) Tablets
• B) Injections
• C) Eye drops
• D) Both B & C

Answer 20

D

Question 21

What is the pH range of pancreatic juice?
• A) 6.3 - 7.5
• B) 1.4 - 2.0
• C) 7.5 - 8.8
• D) 6.0 - 7.2

Answer 21

7.5-8.8

Question 22

What is the molar ratio of salt to acid required to prepare an acetate buffer solution of pH 5 if the pKa of acetic acid is 4.8?
• A) 7:1
• B) 1.58:1
• C) 5:1
• D) 0.2:1

Answer 22

B

Question 23

True or False:
The pH of cerebrospinal fluid is always neutral (7.0).

Answer 23

Falsy – the pH of cerebrospinal fluid is between 7.2 and 7.5.

Question 24

True or False:
Dilution of a buffer with water can change the pH of the solution.

Answer 24

Truey

Question 25

True or False: Acetate buffers decrease in pH when temperature increases.

Answer 25

Falsy – the pH of acetate buffers increases with temperature.

Question 26

The pH of urine ranges between ______ and ______.

Answer 26

4.8 and 7.5

Question 27

When 1 mL of 0.1 M HCl is added to 100 mL of pure water, the pH drops from 7 to ______.

Answer 27

3

Question 28

When a strong acid such as HCl is added to an acetate buffer, the ______ in the buffer ties up the H+ ions to minimize the pH change.

Answer 28

sodium acetate (salt)

Question 29

The pH of sweat can range between ______ and ______.

Answer 29

4.0 and 6.8

Question 30

Why don’t we usually use weak bases and their salts in buffers?

Answer 30

-Their volatility and instability

-their pH depends on pHw which is affected by temperature

Question 31

_____ is the dissociation constant of the weak acid or the weak
base.

Answer 31

pKa

Question 32

T or F:

The buffer system giving the best buffer capacity will be that containing an acid/base with a pKa closest to the desired pH of the solution

Answer 32

True

Question 33

The buffer system giving the best buffer capacity will be that containing an _______ with a ____ closest to the desired ___of the solution

Answer 33

acid/base, pKa, pH

Question 35

True or False:
The pH of saliva is typically more acidic than that of blood.

Answer 35

truey

Question 36

Which fluid in the body is the most alkaline under normal conditions?

A) Gastric juice
B) Urine
C) Pancreatic fluid
D) Blood

Answer 36

c

Question 37

The pH of urine can vary widely, but it typically falls within which range?

A) 5.5 - 7.5
B) 3.0 - 4.0
C) 7.5 - 8.5
D) 4.8 - 7.5

Answer 37

d

Question 38

Which body fluid is closest to neutral pH under normal conditions?

A) Cerebrospinal fluid
B) Gastric juice
C) Blood
D) Pancreatic fluid

Answer 38

a

Question 39

T or F;
The pH of blood is slightly alkaline.

Answer 39

Truey

Question 40

Which buffer system primarily regulates the pH of the blood by balancing bicarbonate and carbonic acid?

A) Phosphate buffer system
B) Protein buffer system
C) Bicarbonate buffer system
D) Ammonia buffer system

Answer 40

C

Question 41

T or F:
The bicarbonate buffer system is the most important buffer system in extracellular fluids, including blood.

Answer 41

Truey

Question 42

T or F:
he phosphate buffer system is the most important buffer system in extracellular fluids, including blood.

Answer 42

Falsy
it’s bicarbonate

Question 43

In addition to the bicarbonate buffer system, which other buffer system plays a significant role in intracellular fluid?

A) Hemoglobin buffer system
B) Protein buffer system
C) Phosphate buffer system
D) Ammonia buffer system

Answer 43

C

Question 44

T or F:
Phosphate buffer system is the most important intracellular fluid buffer

Answer 44

Truey