Chapter 4 - Back to Basics: Acids, Bases, and Ph

1. Chemistry is the study of the ______ of matter.

A. composition and structure

C. interaction

B. properties

D. all of these

D. all of these

A(n) _____ is a substance that cannot be broken down into other substances by ordinary chemical means.

 A. element B. atom C. compound D. molecule

A. element

Matter is anything that occupies space and has ______.

A. area B. mass C. weight D. volume

B. mass

4. The typical human body is composed of approximately 65% _____.

 A. nitrogen B. carbon C. oxygen D. hydrogen

C. oxygen

5. Atoms are composed of which of the following?

 A. protons B. electrons C. neutrons D. all of these

D. all of these

6. You dissolve a teaspoon of sugar in water. The sugar is called the ____.

 A. solvent B. solute C. solution D. electrolyte

B. solute

7. A(n) ________ results from the chemical union of two or more atoms.

 A. molecule B. ion C. element D. neutron

 A. molecule

8. What is the range of the pH scale?

 A. 4–6 B. 0–10 C. 0–14 D. 8–12

C. 0–14

9. Which type of chemical bond results from the equal sharing of electrons?

A. ionic bond

C. polar covalent bond

B. nonpolar covalent bond

D. all of these

B. nonpolar covalent bond

10. An acid is a substance that yields (donates) a _____ ion.

 A. sodium (Na+) C. hydroxide (OH^–)

 B. hydrogen (H+) D. chloride (Cl–)

B. hydrogen (H+)

11. Carbon has an atomic number of 12, which means it has 12 ______.

 A. ions B. isotopes C. protons D. neutrons

C. protons

12. A solution with a pH of _____ is considered neutral.

 A. 2 B. 5 C. 7 D. 9

C. 7

13. Which of the following has a neutral pH?

 A. milk B. beer C. seawater D. pure water

D. pure water

14. Phenolphthalein, which is an indicator solution, becomes ______ in a basic solution and in an acidic solution is _______.

 A. blue, colorless

B. pink, colorless

C. colorless, pink

D. colorless, blue

B. pink, colorless

15. Which of the following has the lowest pH?

 A. stomach acid B. tomatoes C. baking soda D. oven cleaner

 A. stomach acid

16. Bases have which of the following characteristics?

 A. react with certain metals to liberate hydrogen gas

 B. release OH– in solution or decrease the H+ concentration

 C. have a sour taste

 D. neutralize other bases

B. release OH– in solution or decrease the H+ concentration

17. Which of the following is NOT a characteristic of acids?

A. Feel slippery

C. neutralize bases

B. May be corrosive or poisonous.

D. contribute one or more H+

to a solution

A. Feel slippery

18. Indicate whether each of the following is an acid or a base: H2SO4, Mg(OH)2, H3PO4, KOH.

 A. acid, acid, base, base C. base, base, acid, acid

 B. acid, base, acid, base D. base, acid, base, acid

 B. acid, base, acid, base

19. Which of the following plant extracts could be used as a pH indicator?

 A. elderberry D. all of these

 B. hydrangea E. A and B only

 C. purple (red) cabbage

D. all of these

20. Acids turn the methyl orange indicator ______.

 A. orange B. yellow C. red D. blue

C. red

21. Bases turn red litmus paper ______.

 A. blue B. orange C. green D. yellow

 A. blue

22. Which one of the following is NOT used as an indicator to determine whether a substance is an acid or base?

 A. red/blue litmus paper C. methyl orange

 B. phenolphthalein D. methylene blue

D. methylene blue

23. You add the indicator phenolphthalein to a solution with a pH of 8. What color is the solution?

 A. deep blue B. bright pink C. pale green D. colorless

B. bright pink

24. You dip a piece of blue litmus paper in a solution of NaOH. What happens to the color of the litmus paper?

 A. it remains blue B. it turns pink C. it turns yellow D. it turns purple

A. it remains blue

25. If you dip a piece of red litmus paper in a solution of NaOH, it will _______.

 A. remain red B. turn blue C. turn green D. turn white

B. turn blue

26. What happens when you dissolve NaCl in water?

 A. the NaCl dissociates into Na+ and Cl–

 B. the water forms a covalent bond with the NaCl

 C. the water molecules lose their polarity

 D. H+ is released.

A. the NaCl dissociates into Na+ and Cl–

27. A solution with a pH of 4 has _____ times more H+ than a solution with a pH of 6.

 A. 10 B. 100 C. 1,000 D. 10,000

B. 100

28. When Na+ and HCO3– combine, they form a(n) ____ bond.

 A. polar covalent C. ionic

 B. nonpolar covalent D. relatively weak

C. ionic

29. A _____ substance will NOT mix with a _____ substance.

 A. polar, nonpolar C. nonpolar, nonpolar

 B. polar, polar D. B and C

A. polar, nonpolar

30. You have a “sour stomach,” so you take an over-the-counter antacid that relieves your symptoms by _____.

 A. emptying your stomach C. generating OH–

 B. suppressing your appetite D. absorbing excess H+

D. absorbing excess H+