Question 1

What is the pH of a 0.20 M solution of NH4Cl? [Kb(NH3) = 1.8 * 10-5]

Accepted Answer

A)  3.74 
B)  4.98 
C)  6.53 
D)  9.02 
E)  10.25 
A)  3.74 
B)  4.98 
C)  6.53 
D)  9.02 
E)  10.25

Question 2

Calculate the concentration of chromate ion (CrO42-) in a 0.450 M solution of chromic acid (H2CrO4). [For chromic acid, Ka1 = 0.18, Ka2 = 3.2 * 10-7.]

Accepted Answer

A)  3.2 * 10-7 M 
B)  1.5 * 10-6 M 
C)  0.081 M 
D)  1.1 * 10-6 M 
E)  0.21 M 
A)  3.2 * 10-7 M 
B)  1.5 * 10-6 M 
C)  0.081 M 
D)  1.1 * 10-6 M 
E)  0.21 M

Question 3

Which of the following solutions is acidic

Accepted Answer

A)  [H3O+] = 7.0 x 10-7 M 
B)  [H3O+] = 1.5 x 10-10 M 
C)  [H3O+] -7 M 
D)  [H3O+] > 7.0 x 10-7 M 
E)  [H3O+] = 1.0 x 10-14 M 
A)  [H3O+] = 7.0 x 10-7 M 
B)  [H3O+] = 1.5 x 10-10 M 
C)  [H3O+] -7 M 
D)  [H3O+] > 7.0 x 10-7 M 
E)  [H3O+] = 1.0 x 10-14 M

Question 4

Identify the conjugate base of HSO4-.

Accepted Answer

A)  OH- 
B)  H2SO4 
C)  H2O 
D)  H2SO3 
E)  SO42- 
A)  OH- 
B)  H2SO4 
C)  H2O 
D)  H2SO3 
E)  SO42-

Question 5

The equilibrium constant for the reaction C6H5COOH(aq) + CH3COO-(aq) $\leftrightharpoons$ C6H5COO-(aq) + CH3COOH(aq)
Is 3.6 at 25$\circ$C. If Ka for CH3COOH is 1.8 * 10-5, what is the acid dissociation constant for C6H5COOH

Accepted Answer

A)  5.0 * 10-6 
B)  6.5 * 10-5 
C)  2.3 * 10-4 
D)  8.3 * 10-5 
E)  5.6 * 10-6 
A)  5.0 * 10-6 
B)  6.5 * 10-5 
C)  2.3 * 10-4 
D)  8.3 * 10-5 
E)  5.6 * 10-6

Question 6

Kw = 1.0 x 10S1U1P1-14S1S1P0at all temperatures.

Accepted Answer

A) True 
 B)False

Question 7

When comparing acid strength of binary acids HX, as X varies within a particular group of the periodic table, which one of these factors dominates in affecting the acid strength

Accepted Answer

A)  bond strength 
B)  electron withdrawing effects 
C)  percent ionic character of the H-X bond 
D)  solubility 
E)  Le Châtelier's principle 
A)  bond strength 
B)  electron withdrawing effects 
C)  percent ionic character of the H-X bond 
D)  solubility 
E)  Le Châtelier's principle

Question 8

Which of the following solutions is basic

Accepted Answer

A)  [OH-] = 1.0 x 10-14 M 
B)  [OH-] = 1.0 x 10-7 M 
C)  [H3O+] = 1.0 x 10-14 M 
D)  [H3O+] > 1.0 x 10-7 M 
E)  [OH-] -7 M 
A)  [OH-] = 1.0 x 10-14 M 
B)  [OH-] = 1.0 x 10-7 M 
C)  [H3O+] = 1.0 x 10-14 M 
D)  [H3O+] > 1.0 x 10-7 M 
E)  [OH-] -7 M

Question 9

What is the concentration of H+ in a 2.5 M HCl solution

Accepted Answer

A)  0 
B)  1.3 M 
C)  2.5 M 
D)  5.0 M 
E)  10. M 
A)  0 
B)  1.3 M 
C)  2.5 M 
D)  5.0 M 
E)  10. M

Question 10

The pH of a 0.6 M solution of a weak acid is 4.0. What percent of the acid has ionized

Accepted Answer

A)  0.01 % 
B)  0.02 % 
C)  0.03 % 
D)  0.04 % 
E)  None of the above 
A)  0.01 % 
B)  0.02 % 
C)  0.03 % 
D)  0.04 % 
E)  None of the above

Question 11

HCN is classified as a weak acid in water. This classification means that a relatively small fraction of the acid undergoes ionization.

Accepted Answer

A) True 
 B)False

Question 12

Calculate the hydrogen ion concentration in a solution of iced tea with lemon having a pH of 2.87.

Accepted Answer

A)  2.9 * 10-2 M 
B)  5.7 * 10-2 M 
C)  1.3 * 10-3 M 
D)  2.9 * 10-3 M 
E)  5.7 * 10-4 M 
A)  2.9 * 10-2 M 
B)  5.7 * 10-2 M 
C)  1.3 * 10-3 M 
D)  2.9 * 10-3 M 
E)  5.7 * 10-4 M

Question 13

The formula for the conjugate base of HPO42- is H2PO4-.

Accepted Answer

A) True 
 B)False

Question 14

When 2.0 * 10-2 mole of nicotinic acid (a monoprotic acid) is dissolved in 350. mL of water, the pH is 3.05. What is the Ka of nicotinic acid

Accepted Answer

A)  1.0 * 10-5 
B)  1.2 * 10-5 
C)  1.4 * 10-5 
D)  1.6 * 10-5 
E)  None of the above 
A)  1.0 * 10-5 
B)  1.2 * 10-5 
C)  1.4 * 10-5 
D)  1.6 * 10-5 
E)  None of the above

Question 15

What is the pH of a 0.30 M solution of HOCl (Ka = 3.5 x 10-8)

Accepted Answer

A)  7.45 
B)  6.54 
C)  7.98 
D)  5.22 
E)  3.99 
A)  7.45 
B)  6.54 
C)  7.98 
D)  5.22 
E)  3.99

Question 16

Aspartic acid (C4H7NO4), one of the 20 essential amino acids, has two ionizable hydrogens. At 25$\circ$C, Ka1 = 1.38 * 10-4 and Ka2 = 1.51 * 10-10. What is the concentration of doubly ionized aspartate ions in a 0.125 M aqueous solution of aspartic acid

Accepted Answer

A)  3.33 * 10-2 M 
B)  4.16 * 10-3 M 
C)  4.15 * 10-3 M 
D)  1.51 * 10-10 M 
E)  2.08 * 10-14 M 
A)  3.33 * 10-2 M 
B)  4.16 * 10-3 M 
C)  4.15 * 10-3 M 
D)  1.51 * 10-10 M 
E)  2.08 * 10-14 M

Question 17

Calculate the H+ ion concentration in lemon juice having a pH of 2.40.

Accepted Answer

A)  4.0 * 10-2 M 
B)  250 M 
C)  0.38 M 
D)  4.0 * 10-3 M 
E)  12 M 
A)  4.0 * 10-2 M 
B)  250 M 
C)  0.38 M 
D)  4.0 * 10-3 M 
E)  12 M

Question 18

Which of the following solutions is basic

Accepted Answer

A)  [H3O+] = 1.0 x 10-10 M 
B)  [OH-] = 1.0 x 10-10 M 
C)  [H3O+] > 1.0 x 10-7 M 
D)  [OH-] -10 M 
E)  [OH-] = 1.0 x 10-7 M 
A)  [H3O+] = 1.0 x 10-10 M 
B)  [OH-] = 1.0 x 10-10 M 
C)  [H3O+] > 1.0 x 10-7 M 
D)  [OH-] -10 M 
E)  [OH-] = 1.0 x 10-7 M

Question 19

What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH = 4.85? [Kb(NH3) = 1.8 * 10-5]

Accepted Answer

A)  4.7 g 
B)  75 g 
C)  2.3 * 10-3 g 
D)  19 g 
E)  10. g 
A)  4.7 g 
B)  75 g 
C)  2.3 * 10-3 g 
D)  19 g 
E)  10. g

Question 20

The pOH of a solution is 10.40. Calculate the hydrogen ion concentration in the solution.

Accepted Answer

A)  4.0 * 10-11 M 
B)  3.6 M 
C)  4.0 * 10-10 M 
D)  2.5 * 10-4 M 
E)  1.8 * 10-4 M 
A)  4.0 * 10-11 M 
B)  3.6 M 
C)  4.0 * 10-10 M 
D)  2.5 * 10-4 M 
E)  1.8 * 10-4 M

Exam 15: Acids and Bases

What is the pH of a 0.20 M solution of NH4Cl? [Kb(NH3) = 1.8 * 10-5]

Calculate the concentration of chromate ion (CrO42-) in a 0.450 M solution of chromic acid (H2CrO4). [For chromic acid, Ka1 = 0.18, Ka2 = 3.2 * 10-7.]

Which of the following solutions is acidic

Identify the conjugate base of HSO4-.

The equilibrium constant for the reaction C6H5COOH(aq) + CH3COO-(aq) ⇋\leftrightharpoons⇋ C6H5COO-(aq) + CH3COOH(aq) Is 3.6 at 25 ∘\circ∘ C. If Ka for CH3COOH is 1.8 * 10-5, what is the acid dissociation constant for C6H5COOH

Kw = 1.0 x 10-14at all temperatures.

When comparing acid strength of binary acids HX, as X varies within a particular group of the periodic table, which one of these factors dominates in affecting the acid strength

Which of the following solutions is basic

What is the concentration of H+ in a 2.5 M HCl solution

The pH of a 0.6 M solution of a weak acid is 4.0. What percent of the acid has ionized

HCN is classified as a weak acid in water. This classification means that a relatively small fraction of the acid undergoes ionization.

Calculate the hydrogen ion concentration in a solution of iced tea with lemon having a pH of 2.87.

The formula for the conjugate base of HPO42- is H2PO4-.

When 2.0 * 10-2 mole of nicotinic acid (a monoprotic acid) is dissolved in 350. mL of water, the pH is 3.05. What is the Ka of nicotinic acid

What is the pH of a 0.30 M solution of HOCl (Ka = 3.5 x 10-8)

Aspartic acid (C4H7NO4), one of the 20 essential amino acids, has two ionizable hydrogens. At 25 ∘\circ∘ C, Ka1 = 1.38 * 10-4 and Ka2 = 1.51 * 10-10. What is the concentration of doubly ionized aspartate ions in a 0.125 M aqueous solution of aspartic acid

Calculate the H+ ion concentration in lemon juice having a pH of 2.40.

Which of the following solutions is basic

What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH = 4.85? [Kb(NH3) = 1.8 * 10-5]

The pOH of a solution is 10.40. Calculate the hydrogen ion concentration in the solution.

Chemistry: The Study of Change

Atoms Molecules and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Molecular Geometry and Hybridization of Atomic

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

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Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

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Organic Chemistry

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Filters

What is the pH of a 0.20 M solution of NH₄Cl? [K_b(NH₃) = 1.8 * 10^-5]

Calculate the concentration of chromate ion (CrO₄^2-) in a 0.450 M solution of chromic acid (H₂CrO₄). [For chromic acid, K_a1 = 0.18, K_a2 = 3.2 * 10^-7.]

Identify the conjugate base of HSO₄^-.

The equilibrium constant for the reaction C₆H₅COOH(aq) + CH₃COO^-(aq) $\leftrightharpoons$ C₆H₅COO^-(aq) + CH₃COOH(aq) Is 3.6 at 25^$\circ$C. If K_a for CH₃COOH is 1.8 * 10^-5, what is the acid dissociation constant for C₆H₅COOH

K_w = 1.0 x 10^-14at all temperatures.

What is the concentration of H⁺ in a 2.5 M HCl solution

The formula for the conjugate base of HPO₄^2- is H₂PO₄^-.

When 2.0 * 10^-2 mole of nicotinic acid (a monoprotic acid) is dissolved in 350. mL of water, the pH is 3.05. What is the K_a of nicotinic acid

What is the pH of a 0.30 M solution of HOCl (K_a = 3.5 x 10^-8)

Aspartic acid (C₄H₇NO₄), one of the 20 essential amino acids, has two ionizable hydrogens. At 25^$\circ$C, K_a1 = 1.38 * 10^-4 and K_a2 = 1.51 * 10^-10. What is the concentration of doubly ionized aspartate ions in a 0.125 M aqueous solution of aspartic acid

Calculate the H⁺ ion concentration in lemon juice having a pH of 2.40.

What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH = 4.85? [K_b(NH₃) = 1.8 * 10^-5]