1. KOH
2. KCl
3. CH₃OH
4. CH₃COOH

Correct Answer Number: 2

Explanation: See Ref. Table K.    CH₃COOH is an organic acid, acetic acid also called ethanoic acid. Choice 1 will yield the OH^- ion in solution (this compound is therefore a base, See Table L). Choice 3 is an alcohol, See Table R. Salts are ionic compounds that do not form OH^- or H⁺ ions. KCl forms K⁺ and Cl^- ions. Therefore it is a salt.

1. HCL
2. NaCl
3. LiOH
4. KOH

Correct Answer Number: 1

Explanation: By definition an Arrhenius acid yields hydrogen ions as the only positive ions in aqueous solution. Choice 2 is a salt. Choice 3 forms Li⁺ and OH^- ions; choice 4 also forms OH^- ions: these compounds are Arrhenius bases. Choice 1 forms H⁺ ions and is therefore an Arrhenius acid.

1. HCl(aq)
2. NaCl(aq)
3. CH₃OH(aq)
4. NaOH(aq)

Correct Answer Number: 4

Explanation: Red litmus turns blue when a base is present. Hint: blue for base. Choice 1 is an acid; choice 2 is a salt and salts neutralize acids and bases. The litmus does not change color with salts. Choice 3 is an alcohol not a base. It is not found on Ref. Table L. NaOH is a strong base and will change red litmus to blue.

1. 7
2. 10
3. 3
4. 14

Correct Answer Number: 3

Explanation: On the pH scale, a pH of less than 7 is acidic; a pH of more than 7 is basic. A neutral solution such as pure water has a pH of 7.

1. 1
2. 9
3. 5
4. 4

Correct Answer Number: 3

Explanation: By definition pH is the negative log (logarithm) of the hydronium ion concentration. A 0.00001 molar solution has a H⁺ concentration of 10^-5 M (move the decimal point 5 places to the right). The value of the negative exponent (^-5) gives a pH of 5. See also #7 and #19, this topic.

1. 1
2. 2
3. 10
4. 14

Correct Answer Number: 2

Explanation: By definition pH is the negative log (logarithm) of the hydronium ion concentration. A 0.01 molar solution has a H⁺ concentration of 10^-2 (move the decimal point 2 places to the right). The value of the negative exponent (^-2) gives a pH of 2. See also #6 and #19, this topic.

1. donate a proton
2. donate an electron
3. accept a proton
4. accept an electron

Correct Answer Number: 1

Explanation: According to Bronsted-Lowry theory, an acid is any species that can donate a proton to another species.

1. HBr(aq)
2. CO₂(aq)
3. LiOH(aq)
4. CH₃OH(aq)

Correct Answer Number: 3

Explanation: Different indicators change color at differing concentrations of hydrogen ions. Phenolphthalein turns pink in basic solutions that range from about 8.2 to 10 and colorless in acid solutions.(See Table M) Since the question wants it to turn pink, you are looking for a base.
Choice 4 is an alcohol: it is neutral in water. Locate choices 1 and 2 on Ref. Table K. Note that they are acidic in water. Group 1 elements of the Periodic Table (Li, Na and K) form strong bases when combined with hydroxide (OH)^-. When dissolved in water, LiOH makes a strongly basic solution.(Table L) It will turn phenolphthalein pink.

1. esterification
2. decomposition
3. hydrolysis
4. neutralization

Correct Answer Number: 4

Explanation: By definition neutralization occurs when equal quantities of an acid (H⁺) react with equal quantities of a base (OH^-) to form water.

1. always less than the concentration of the hydroxide ions
2. always greater than the concentration of the hydroxide ions
3. always equal than the concentration of the hydroxide ions
4. sometimes greater and sometimes less than the concentration of the hydroxide ions

Correct Answer Number: 3

Explanation: Answer 4 is impossible. Neutralization means equivalent amounts of hydronium and hydroxide ions react in solution to produce water. Water has a pH of 7. By definition, only answer 3 is correct.

1. decrease
2. increase
3. remain the same

Correct Answer Number: 1

Explanation: (OH^-) multiplied by (H₃O⁺) is a constant number equal to 1 x 10^-14 for aqueous solutions. In other words, (A) (B) = -14. Substituting numbers, (-7) (2) = -14.
But if 7 is increased to 14, 2 must decrease to -1 to keep the answer -14. (14) (-1) =-14.
If (H₃O⁺) increases, (OH^-) must decrease.

1. adding 50 mL of 12 M HCl to 50 mL of water while stirring the mixture steadily.
2. adding 50 mL of 12 M HCl to 50 mL of water and then stirring the mixture steadily.
3. adding 50 mL of water to 50 mL of 12 M HCl while stirring the mixture steadily.
4. adding 50 mL of water to 50 mL of 12 M HCl and then stirring the mixture steadily.

Correct Answer Number: 1

Explanation: Safety Rule: always add acid to water; This prevents the acid from splattering. Never add water to acid. Place a glass stirring rod in the water and slowly pour the acid along the rod. Some concentrated acids like HCl have an exothermic reaction in water, releasing a large amount of heat and causing the water-acid solution to boil. Constant stirring diffuses the acid throughout the solution, helping to evenly distribute the generated heat.

1. 1.6 M
2. 0.64 M
3. 0.31M
4. 0.13M

Correct Answer Number: 3

Explanation: Using the titration method, the volume of acid x the molarity of the acid neutralizes an equal volume of base x the molarity of the base. Or
V_Acid x M_Acid = V_Base x M_Base where V = volume and M = molarity of HCl and NaOH.
You are looking for the molarity of HCL or
(14.4 mL) (M of HCl) = (22.4 mL) ( 0.20M).
Rearranging terms, M of NaOH = (22.4 mL) (0.20 M) / 14.4 mL = 0.31 M.
See #12 , Acids and Bases. See also Reference Table T for formulas.