HW05 - Acids, Bases, and Salts

Question 11.0 pts

In the reversible reaction

HCN + H2O ⇌ CN- + H3O+,

the two Bronsted-Lowry acids are...

  1. There is only one Bronsted-Lowry acid shown: H3O+.
  2. H2O and CN-
  3. HCN and CN-
  4. HCN and H3O+
  5. H2O and H3O+

Question 21.0 pts

A water solution of sodium acetate is basic because...
  1. the acetate ion acts as a Bronsted-Lowry base in a reaction with water.
  2. The statement is false. A water solution of sodium acetate is acidic.
  3. sodium acetate is only weakly ionized.
  4. the conjugate base of the acetate ion is a strong base.

Question 31.0 pts

According to the Bronsted-Lowry concept of acids and bases, which of the following statements about a base is NOT true?
  1. A base will share one of its electron pairs to bind H+.
  2. A base reacts with an acid to form a salt.
  3. If a base is strong, then its conjugate acid will be relatively weaker.
  4. A base must contain a hydroxide group.

Question 41.0 pts

Which of the following is true in pure water at any temperature?
  1. pH = 7.0
  2. [H3O+][OH-] = 1.0 x 10-14
  3. Kw decreases with increasing temperature.
  4. [H3O+] = [OH-]

Question 51.0 pts

What is [H3O+] when [OH-] = 3.3 x 10-9 M?
  1. 3.0 x 10-6 M
  2. 3.3 x 10-5 M
  3. 1.0 x 10-7 M
  4. 3.3 x 10-9 M

Question 61.0 pts

A strong acid (or base) is one which...
  1. dissociates completely in aqueous solution.
  2. should only be used when wearing goggles and gloves.
  3. dissolves metals.
  4. reacts with a salt to form water.

Question 71.0 pts

Which of the following substances is a strong acid?
  1. H3PO4
  2. HSO3
  3. H2CO3
  4. HF
  5. H2SO4

Question 81.0 pts

HCN is classified as a weak acid in water. This means that it produces...
  1. no hydronium ions.
  2. a relatively small fraction of the maximum number of possible hydronium ions.
  3. 100% of the maximum number of possible hydronium ions.
  4. a relatively large fraction of the maximum number of possible hydronium ions.

Question 91.0 pts

Which of the following substances is a weak acid?
  1. HI
  2. HClO4
  3. HClO3
  4. H2CO3
  5. HBr
  6. HNO3
  7. H2SO4
  8. HCl

Question 101.0 pts

Which is NOT a conjugate acid-base pair, respectively?
  1. HCN : CN-
  2. H2O : OH-
  3. SO42- : HSO4-
  4. H3O+ : H2O

Question 111.0 pts

The conjugate base of H2SO4 is:
  1. HSO4-
  2. SO42-
  3. HSO4
  4. H3SO4+

Question 121.0 pts

What is the conjugate acid of NO3-?
  1. NH3
  2. HNO3
  3. NO32-
  4. NO2-

Question 131.0 pts

Assume that five weak acids, identified only by numbers (1, 2, 3, 4, and 5) have the following ionization constants:

1 -     1.0 x 10-3

2 -     3.0 x 10-5

3 -     2.6 x 10-7

4 -     4.0 x 10-9

5 -     7.3 x 10-11

The anion of which acid is the strongest base?

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

Question 141.0 pts

The term "Ka for the ammonium ion" describes the equilibrium constant for which of the following reactions?
  1. NH4+ + H2O ⇌ NH3 + H3O+
  2. NH4+ + OH- ⇌ NH3 + H2O
  3. NH3 + H2O ⇌ NH4+ + OH-
  4. NH4Cl(solid) + H2O ⇌ NH4+ + Cl-

Question 151.0 pts

If the value of Kb for pyridine (C5H5N) is 1.8 x 10-9, calculate the equilibrium constant for the following reaction:

C5H5NH+(aq) + H2O(l) \leftrightharpoons C5H5N(aq) + H3O+(aq)

  1. -1.8 x 10-9
  2. 5.6 x 10-6
  3. 1.8 x 10-16
  4. 5.6 x 108

Question 161.0 pts

What is [OH-] in a 0.0050 M HCl solution?
  1. 2.0 x 10-12 M
  2. 1.0 x 10-7 M
  3. 1.0 M
  4. 6.6 x 10-5

Question 171.0 pts

Which pH represents a solution with 1000 times higher [OH-] than a solution with a pH of 5?
  1. pH = 4
  2. pH = 7
  3. pH = 8
  4. pH = 6

Question 181.0 pts

What is the pH of a 0.1 M Ba(OH)2 aqueous solution?
  1. 1.33
  2. 8.7
  3. 13.3
  4. 9.98

Question 191.0 pts

Hydroxylamine is a weak molecular base with Kb = 6.6 x 10-9. What is the pH of a 0.0500 M solution of hydroxylamine?
  1. 10.4
  2. 9.48
  3. 9.26
  4. 8.93

Question 201.0 pts

What is the pH of a 0.23 M solution of potassium generate (KR-COO)? Ka for the generic acid R-COOH is 2.7 x 10-8.
  1. 10.83
  2. 10.23
  3. 10.60
  4. 10.47

Question 211.0 pts

Which solution has the highest pH?
  1. 0.1 M KClO, Ka for HClO is 3.5 x 10-8
  2. 0.1 M of KNO2, Ka for HNO2 is 4.5 x 10-4
  3. 0.1 M of KCl, Ka for HCl is VERY LARGE!!
  4. 0.1 M KCH3COO, Ka for CH3COOH is 1.8 x 10-5

Question 221.0 pts

What is the pH of a solution that contains 11.7g of NaCl for every 200 mL of solution?
  1. 9.0
  2. 7.0
  3. 10-1
  4. 1.0 x 10-7

Question 231.0 pts

What is the pH of a solution made by mixing 0.050 mol of NaCN with enough water to make a liter of solution? Ka for HCN is 4.9 x 10-10.
  1. 12
  2. 11
  3. 10-3
  4. 3

Question 241.0 pts

Identify the list in which all salts produce a basic aqueous solution.
  1. KCH3COO, NaCN, KF
  2. NH4Cl, C6H4NH3NO3, FeI3
  3. AgNO3, NaCHO2, CrI3
  4. AlCl3, Zn(NO3)2, KClO4

Question 251.0 pts

What is the pH in a solution made by dissolving 0.100 moles of sodium acetate (NaCH3COO) in enough water to make one liter of solution? Ka for CH3COOH is 1.80 x 10-5.
  1. 10.25
  2. 8.87
  3. 5.74
  4. 9.25

Question 261.0 pts

A 0.200 M solution of a weak monoprotic acid HA is found to have a pH of 3.00 at room temperature. What is the ionization constant of this acid?
  1. 5.3
  2. 5.0 x 10-6
  3. 1.0 x 10-3
  4. 2.0 x 10-9

Question 271.0 pts

What is the percent ionization for a weak acid HX that is 0.40 M? Ka = 4.0 x 10-7.
  1. 0.0010%
  2. 0.20%
  3. 0.10%
  4. 0.0020%

Question 281.0 pts

A 0.28 M solution of a weak acid is 3.5% ionized. What is the pH of the solution?
  1. 0.55
  2. 2.01
  3. 1.46
  4. 3.17

Question 292.0 pts

The pH of 0.010 M aqueous aniline is 8.32. What is the percentage protonated?
  1. 0.021%
  2. 0.0021%
  3. It is impossible to tell without knowing the Ka or the Kb for aniline.
  4. 2.1%