Test Bank For Introduction to the Chemistry of Food, Edition 1 By Michael Zeece

Test Bank For
Introduction to the Chemistry of Food, Edition 1 By Michael Zeece
Chapters 1-8

Introduction to the Chemistry of Food_Zeece 1e_2020


Test Bank: Acids_Bases
1. Water molecules rapidly and reversibly dissociate to form:
a. hydrogen ions
b. hydroxide ions
c. hydrogen gas
d. *hydrogen and hydroxide ions

2. The term pH is used to represent the hydrogen ion concentration of a solution. pH is defined as:
a. *the negative log of the hydrogen ion concentration
b. the inverse of the hydrogen ion concentration
c. the hydrogen ion concentration expressed as a prime number
d. the hydrogen ion concentration of water relative to HCl

3. The concentration of hydrogen ion of pure water is about 0.0000001 M molar. This number
expressed in scientific notation is:
a. *1.0 x 10-7 molar
b. 2.0 x 10-1 molar
c. 7.0 x 10-1 molar
d. 2.0 x10-7 molar

4. The hydrogen ion concentration of pure water (1.0 x 10-7) is equal to a pH of:
a. -7
b. *7
c. 1.0
d. 2

5. A weak acid is defined as a substance that:
a. dissociates completely into hydrogen ions
b. *dissociates partly into hydrogen ions
c. is poorly soluble
d. poorly neutralizes strong bases like sodium hydroxide

6. Which of the following is not a weak acid?
a. *HCl (hydrochloric acid)
b. CH3CO2H (acetic acid)
c. H2CO3 (carbonic acid)
d. C6H8O7 (citric acid)

7. The equation for dissociation of a weak acid HA , can be written as:
a. HA --> H+ + A-
b. HA <-- H+ + A-
c. *HA <---> H+ + A- and HA <-- H+ + A-


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, d. HA <-- H- + A+


8. Buffering is defined as the ability to:
a. prevent change in pH when an acid or base is added
b. prevent change in pH over time
c. resist change in pH when the temperature is increased
d. *resist change in pH when an acid or base is added


9. The term pKa is defined as:
a. The log of the Ka value
b. *The negative log of the Ka value
c. The Ka value expressed in scientific notation
d. Percent of acid dissociated

10. pKa values indicate the strength of an acid. Acids with a low pKa are_________ compared to
those with a higher pKa
a. weaker
b. no different
c. *stronger
d. much weaker

11. Which of the weak acids listed below is the stronger acid?
a. *Tartaric (pKa 3.0)
b. Malic (pKa 3.4)
c. Lactic (pKa 3.9)
d. Carbonic (pKa 6.3)

12. A strong acid is defined as a molecule that:
a. dissociates partially in water
b. *dissociates completely in water
c. dissociates only after heating
d. dissociates under pressure

13. An example of a strong acid is:
a. acetic (CH3CO2H)
b. propionic (CH3CH2COOH)
c. *hydrochloric (HCl)
d. phosphoric (H3PO4 )

14. Increasing the concentration of hydrogen ions in a solution by a factor of ten, results in:
a. increased pH by one unit
b. *decreased pH by one unit
c. increased pH by one tenth of a unit
d. decreased pH by a tenth of a unit




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,15. The pH of a 0.01 molar solution of HCl is:
a. 0
b. *2
c. 20
d. 100


16. An acid will neutralize:
a. protons
b. *a base
c. electrons
d. methane

17. A weak acid that is commonly found in food is:
a. citric
b. malic
c. butyric
d. *all of the above

18. The pH of a typical soft drink is 4. This means that the hydrogen ion concentration in the soft
drink is:
a. 4 molar
b. 0.4 molar
c. 0.0004 molar
d. *0.0001 molar

19. Vinegar is used as a condiment and ingredient. Its major component is:
a. *acetic acid
b. lactic acid
c. carbonic acid
d. butic acid

20. Baking powder is used as a source of CO2 to cause a rise in baked goods without the use of yeast.
The source of CO2 gas in baking powder is:
a. citric acid
b. potassium bitartrate
c. *sodium bicarbonate
d. glucose

21. Potassium bitartrate (cream of tartar) has several uses in food, including:
a. improving the stability of egg whites
b. producing CO2 gas in combination with baking powder
c. stabilizing whipped cream
d. *all of the above




22. The acid produced by the stomach to aid digestion is:
a. acetic acid
b. butyric acid


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, c. lactic acid
d. *hydrochloric acid

23. The low pH of stomach acid aids in digestion of proteins because:
a. low pH makes protein more soluble
b. *low pH denatures proteins making it easier for digestive enzymes to break them down
c. low pH results in ionization of proteins
d. low pH causes CO2 to be produced

24. The source of lactic acid in fermented milk products such as yogurt is:
a. CO2
b. *lactose
c. fructose
d. milk protein

25. The major products of fermentation in making beer are:
a. *ethanol CO2
b. ethanol and lactic acid
c. ethanol and malic acid
d. acetic acid and CO2

26. Fermentation of milk to make yogurt preserves this food by:
a. increasing its pH
b. *decreasing its pH
c. precipitating milk proteins
d. killing microbial pathogens

27. The tingly taste of beer and other carbonated beverages results from activation of:
a. taste bud receptors
b. olfactory receptors
c. *pain receptors
d. acid channels

28. Drinking carbonated beverages creates a pleasurable sensation because:
a. dissolved CO2 creates hydrochloric acid that activates a salt taste bud receptor
b. dissolved CO2 that activates taste bud receptors for sweetness
c. *dissolved CO2 creates carbonic acid activating an enzyme and causing an enjoyable
sensation in the brain
d. dissolved CO2 creates lactic acid that activates a sour taste bud receptor

29. An example of a food with alkaline pH is:
a. tomatoes
b. potatoes
c. oranges
d. *egg white

30. Potassium bitartrate is the potassium salt of:
a. acetic acid
b. lactic acid
c. citric acid
d. *tartaric acid


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