Fill in the blanks. Then highlight the paragraph to check your responses.
In a neutral solution, moles of (1) hydrogen ions equal the moles of (2) hydroxide ions . A pH of 7 indicates that a solution is (3) neutral ; a ph less than 7 would mean the solution is (4) acidic ; and a pH greater than 7 is a(n) (5) basic solution.
Acids have a (6) sour taste, react with metals to produce (7) hydrogen gas, turn (8) indicators different colors according to pH, and are (9) electrolytes because their water solutions conduct electricity. On the other hand, bases have a (10) bitter taste, feel (11) slippery , turn (12) indicators different colors according to pH, and are (13) electrolytes because their water solutions conduct electricity. Most cleaning products are (14) basic , while most foods are (15) acidic . Bases turn litmus (16) blue , phenolphthalein (17) hot pink , and cabbage juice (18) green . Acids turn litmus (19) red , phenolphthalein (20) colorless , and cabbage juice (21) red (or pink) .
Choices (may be used more than once)
| acidic | basic | bitter |
| blue | colorless | electrolytes |
| green | hot pink | hydrogen |
| hydrogen ions | hydroxide ions | Indicators |
| neutral | red | red (or pink) |
| slippery | sour |
Match the items on the left to the items on the right. Then click on Answers to check your responses.
| 1. titration | A. An acid releases hydrogen ions in a water solution and a base releases hydroxide ions in a water solution. | |
| 2. electrolyte | B. The point in a titration when the indicator changes color. | |
| 3. end point | C. A substance whose water solution conducts an electric current. | |
| 4. salt | D. A laboratory method to determine the concentration of an unknown solution of acid or base using a standard. | |
| 5. Arrhenius definition of an acid and a base | E. A compound formed when the positive ion of a base and the negative ion of an acid during a neutralization reaction. |
Answers
1. D 2. C 3. B 4. E 5. A
Name this acid (Click on Answer to check your responses.)
HI
Answer
hydroiodic acid
HNO3
Answer
nitric acid
H2SO3
Answer
sulfurous acid
H3PO4
Answer
phosphoric acid
Name these bases and salts:
KOH
Answer
potassium hydroxide
MgSO4
Answer
magnesium sulfate
Click on the word Answer to check your response.
Write formulas for these acids:
hydrofluoric acid
Answer
HF
phosphorous acid
Answer
H3PO3
Calculate the pH of a 1.4 x 10-2 M NaOH solution.
Answer
[H+][OH–] = 1.0 x 10-14
[H+][1.4 x 10-2] = 1.0 x 10-14
pH = -log [H+] = -log [7.1 x 10-13]
pH = 12
Calculate the [H+] of a solution with a pH = 3.2.
Answer
pH = -log [H+]
3.2 = -log [H+]
[H+] = 6.3 x 10-4 M
Calculate the [OH–] of a solution with a [H+] of 9.3 x 10-4 M.
Answer
[H+][OH–] = 1.0 x 10-14
[9.3 x 10-14][OH–] = 1.0 x 10-14
[OH–] = 1.0 x 10-11 M
In a titration, 25.0 mL of a 0.20 M NaOH solution is used to neutralize 10.0 mL of HCl.
a. Write the equation for this neutralization reaction.
Answer
NaOH + HCl —–> H2O + NaCl
b. Calculate the molarity of the acid.
Answer
In a titration, 24.2 mL of 0.120 M Mg(OH)2 were required to neutralize 33.1 mL of H3PO4.
a. Write the equation for this neutralization reaction.
Answer
2H3PO4 + 3MG(OH)2 ——-> 6H2O +Mg3(PO4)2
b. Calculate the molarity of the acid.
Answer
What is the word equation for the neutralization of a strong acid and strong base?
Answer
acid + base ——-> salt + water