Test Review for

pH and Redox

Teacher Copy

1. TRUE or FALSE

The pH of hair relaxers is basic (alkaline)

1. TRUE

• Hair relaxers usually have a pH between 11-13

2. SHORT ANSWER

• What happens to hair when the pH is above 13 or

below 1?

2. It dissolves

• Hair dissolves completely when the pH is VERY high or VERY low

3. MULTIPLE CHOICE• Which of the following is the most

likely pH for the ends of long hair?

A. 16

B. 14

C. 6.5

D. 5

E. 1

3. C

• Hair becomes more alkaline the further it is away from the scalp. The ends of hair may have a pH 1 to 2 pH points higher than that of hair right next to the scalp.

4. MULTIPLE CHOICE

• Which of the following substances is an oxidizing agent?

• A. H2O2

• B. perborate• C. ammonia• D. Ammonium thioglycolate• E. Both A. and B. are correct

4. A.

Other oxidizing agents are:• H2O2

• Ammonia and ammonium thioglycolate are reducing agents

5. SHORT ANSWER

• How would you describe a combustion reaction?

5. A rapid oxidation that releases energy in the form of heat and light

6. SHORT ANSWER

• A pH of 8.0 is ___ times more basic than a pH of 6.0

6. 100

• pH changes by a factor of 10 between each number on the pH scale

7. TRUE or FALSE

• A solution with a pH of 9.0 can be more acidic than a solution with a pH 7.0

7. FALSE

• A pH number can only be more BASIC than any number smaller than itself

• Conversely, a pH number can only be more ACIDIC than any number larger than itself

8. SHORT ANSWER

• What is a good pH range for skin care products?

8. pH 4 - pH 8

9. SHORT ANSWER

• An ion with a negative charge is called a(n) ___.

9. anion

10. MULTIPLE CHOICE• Which pH number would contain

the most hydroxide ions?A. 7B. 7.5C. 10D. 3E. 1

10. C

• As the pH number ↑, the number of OH – ions also ↑

11. TRUE or FALSE

• In an aqueous solution, as the H+ concentration ↑ the OH – ↓

11. TRUE

12. TRUE or FALSE

• As the pH number ↑ the solution becomes more acidic.

12. FALSE

• As pH number increases the solution becomes more basic (alkaline)

13. TRUE or FALSE

• The products of a neutralization reaction (when an acid and a base react) are always salt and water.

13. TRUE

14. TRUE or FALSE

• pH is a physical property

14. True

15. SHORT ANSWER

• When heat is released during a process, that process is said to be ___.

15. exothermic

16. SHORT ANSWER

• Why are most skin and hair care products pH balanced?

16. To be more compatible with the pH of skin and hair

17. TRUE or FALSE

• pH balanced skin and hair care products cannot hurt the skin and hair

17. FALSE

• pH balancing does not automatically make the product better for the skin and hair; pH blanced products may still contain allergens or irritants

18. TRUE or FALSE

• In pure water the hydrogen (hydronium) ion concen-tration is equal to the hydroxide ion concentration.

18. TRUE

19. SHORT ANSWER

• Would an aqueous solution that causes the cuticle scales to lie down and become smooth be more likely to be acidic or basic?

19. acidic

• Mildly acidic solutions cause the hair to ‘harden’ (cuticle scales to lie down)

20. MULTIPLE CHOICE

The hydrogen ion concentration of a strong acid is ___ than that of pure water.

A.Equal to

B.More than

C.Less than

20. B

• The stronger the acid the more H+ the acid has compared to that of water

21. SHORT ANSWER

• Name two salon services that depend on oxidation-reduction reactions.

21.

Bleachingpermanent waving

tintingrelaxing

22. MULTIPLE CHOICE

• When water ionizes, it splits into ___.

• A. 2 hydroxide ions

• B. 2 hydrogen (hydronium) ions

• C. 2 hydroxide and 2 hydronium ions

• D. 1 hydroxide and 1 hydronium ion

• E. 2 hydronium and 1 hydroxide ion

22. D

• H2O → H+ + OH –

23. SHORT ANSWER

• When a substance is oxidized, what 2 things may happen?

23.

The substance may:

gain oxygenor

lose hydrogen

24. SHORT ANSWER

• A substance that releases oxygen is a(n) ___.

24. Oxidizing agent