Question 1

What is the pH of pure water at 40.0 °C if the Kw at this temperature is 2.92 × 10-14?

Accepted Answer

A) 6.767 
B) 0.465 
C) 7.000 
D) 7.233 
E) 8.446 
A) 6.767 
B) 0.465 
C) 7.000 
D) 7.233 
E) 8.446 A

Question 2

Which of the following is a weak acid?

Accepted Answer

A) HClO4 
B) H2SO4 
C) HCl 
D) HCO2H 
E) HNO3 
A) HClO4 
B) H2SO4 
C) HCl 
D) HCO2H 
E) HNO3 D

Question 3

Determine the Ka for CH3NH3+ at 25 °C.The Kb for CH3NH2 is 4.4 × 10-4.

Accepted Answer

A) 3.1 × 10-10 
B) 6.8 × 10-11 
C) 5.6 × 10-10 
D) 2.3 × 10-3 
E) 2.3 × 10-11 
A) 3.1 × 10-10 
B) 6.8 × 10-11 
C) 5.6 × 10-10 
D) 2.3 × 10-3 
E) 2.3 × 10-11 E

Question 4

Which of the following is a strong acid?

Accepted Answer

A) C6H5CO2H 
B) HCN 
C) HClO4 
D) NH4+ 
E) H2O 
A) C6H5CO2H 
B) HCN 
C) HClO4 
D) NH4+ 
E) H2O

Question 5

Which one of the following salts,when dissolved in water,produces the solution with a pH closest to 7.00?

Accepted Answer

A) NH4ClO4 
B) NaO 
C) NaCO3 
D) KI 
A) NH4ClO4 
B) NaO 
C) NaCO3 
D) KI

Question 6

Determine the [OH-] concentration of a 0.116 mol L-1 Ba(OH)2 solution at 25 °C.

Accepted Answer

A) 4.310 × 10-14 mol L-1 
B) 0.116 mol L-1 
C) 0.232 mol L-1 
D) 8.62 × 10-14 mol L-1 
E) 0.058 mol L-1 
A) 4.310 × 10-14 mol L-1 
B) 0.116 mol L-1 
C) 0.232 mol L-1 
D) 8.62 × 10-14 mol L-1 
E) 0.058 mol L-1

Question 7

Which one of the following salts,when dissolved in water,produces the solution with the highest pH?

Accepted Answer

A) NaHCO3 
B) KClO4 
C) Na2CO3 
D) CH3NH3Cl  
A) NaHCO3 
B) KClO4 
C) Na2CO3 
D) CH3NH3Cl

Question 8

What is the autoionization of water?

Accepted Answer

Autoionization of water is the equilibri

Question 9

Calculate the pH of a solution that contains 3.9 × 10-4 mol L-1 H3O+ at 25 °C.

Accepted Answer

A) 4.59 
B) 3.41 
C) 10.59 
D) 9.41 
E) 0.59 
A) 4.59 
B) 3.41 
C) 10.59 
D) 9.41 
E) 0.59

Question 10

Which of the following acids is the strongest? The acid is followed by its Ka value.

Accepted Answer

A) HF,3.5 × 10-4 
B) HCN,4.9 × 10-10 
C) HNO2,4.6 × 10-4 
D) HCHO2,1.8 × 10-4 
E) HClO2,1.1 × 10-2 
A) HF,3.5 × 10-4 
B) HCN,4.9 × 10-10 
C) HNO2,4.6 × 10-4 
D) HCHO2,1.8 × 10-4 
E) HClO2,1.1 × 10-2

Question 11

Determine the pOH of a 0.188 mol L-1 NH3 solution at 25 °C.The Kb of NH3 is 1.76 × 10-5.

Accepted Answer

A) 5.480 
B) 2.740 
C) 8.520 
D) 11.260 
E) 12.656 
A) 5.480 
B) 2.740 
C) 8.520 
D) 11.260 
E) 12.656

Question 12

Identify the diprotic acid.

Accepted Answer

A) HNO3 
B) HCl 
C) CH3COOH 
D) H2SO4 
E) HClO4 
A) HNO3 
B) HCl 
C) CH3COOH 
D) H2SO4 
E) HClO4

Question 13

Calculate the hydroxide ion concentration in an aqueous solution with a pH of 4.33 at 25 °C.

Accepted Answer

A) 2.1 × 10-10 mol L-1 
B) 9.7 × 10-10 mol L-1 
C) 4.7 × 10-5 mol L-1 
D) 3.8 × 10-5 mol L-1 
E) 6.3 × 10-6 mol L-1 
A) 2.1 × 10-10 mol L-1 
B) 9.7 × 10-10 mol L-1 
C) 4.7 × 10-5 mol L-1 
D) 3.8 × 10-5 mol L-1 
E) 6.3 × 10-6 mol L-1

Question 14

Calculate the concentration of H3O+ in a solution that contains 5.5 × 10-5 mol L-1 OH- at 25 °C.Also identify the solution as acidic,basic,or neutral.

Accepted Answer

A) 1.8 × 10-10 mol L-1,basic 
B) 1.8 × 10-10 mol L-1,acidic 
C) 5.5 × 10-10 mol L-1,neutral 
D) 9.2 × 10-1 mol L-1,acidic 
E) 9.2 × 10-1 mol L-1,basic 
A) 1.8 × 10-10 mol L-1,basic 
B) 1.8 × 10-10 mol L-1,acidic 
C) 5.5 × 10-10 mol L-1,neutral 
D) 9.2 × 10-1 mol L-1,acidic 
E) 9.2 × 10-1 mol L-1,basic

Question 15

Calculate the concentration of bicarbonate ion,HCO3-,in a 0.010 mol L-1 H2CO3 solution that has the stepwise dissociation constants Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11.

Accepted Answer

A) 6.6 × 10-5 mol L-1 
B) 4.3 × 10-7 mol L-1 
C) 4.3 × 10-9 mol L-1 
D) 5.6 × 10-11 mol L-1 
A) 6.6 × 10-5 mol L-1 
B) 4.3 × 10-7 mol L-1 
C) 4.3 × 10-9 mol L-1 
D) 5.6 × 10-11 mol L-1

Question 16

What is the hydroxide ion concentration and the pH for a hydrochloric acid solution that has a hydronium ion concentration of $1.50 \times 10 ^{- 2 }\mathrm {~mol} \mathrm {~L}^{ - 1 }?$

Accepted Answer

A) 6.67 × 10-12 mol L-1,2.82 
B) 6.67 × 10-12 mol L-1,11.18 
C) 6.67 × 10-13 mol L-1,1.82 
D) 6.67 × 10-13 mol L-1,12.17 
A) 6.67 × 10-12 mol L-1,2.82 
B) 6.67 × 10-12 mol L-1,11.18 
C) 6.67 × 10-13 mol L-1,1.82 
D) 6.67 × 10-13 mol L-1,12.17

Question 17

What is the pH of a 0.30 mol L-1 pyridine solution that has Kb = 1.9 × 10-9? The equation for the dissociation of pyridine is below: $$\mathrm { C } _ { 5 } \mathrm { H } _ { 5 } \mathrm {~N} ( a q ) + \mathrm { H } _ { 2 } \mathrm { O } ( l ) \rightleftharpoons \mathrm { C } _ { 5 } \mathrm { H } _ { 5 } \mathrm { NH } ^ { - } ( a q ) + \mathrm { OH } ^ { - } ( a q )$$

Accepted Answer

A) 4.62 
B) 8.72 
C) 9.38 
D) 10.38 
A) 4.62 
B) 8.72 
C) 9.38 
D) 10.38

Question 18

Identify the Lewis acid,Lewis base,and Lewis acid-base adduct in the following equation: 
(C2H5)2O + BF3 ⇌ (C2H5)2O:BF3

Accepted Answer

A) (C2H5)2O is a Lewis base,BF3 is a Lewis acid,and (C2H5)2O:BF3 is a Lewis acid-base adduct. 
B) (C2H5)2O is a Lewis acid,BF3 is a Lewis base,and (C2H5)2O:BF3 is a Lewis acid-base adduct. 
C) (C2H5)2O is a Lewis acid-base adduct,BF3 is a Lewis acid,and (C2H5)2O:BF3 is a Lewis base. 
D) (C2H5)2O is a Lewis base,BF3 is a Lewis acid-base adduct,and (C2H5)2O:BF3 is a Lewis acid adduct. 
E) (C2H5)2O and BF3 are both Lewis acid-base adducts and (C2H5)2O:BF3 is a Lewis acid. 
A) (C2H5)2O is a Lewis base,BF3 is a Lewis acid,and (C2H5)2O:BF3 is a Lewis acid-base adduct. 
B) (C2H5)2O is a Lewis acid,BF3 is a Lewis base,and (C2H5)2O:BF3 is a Lewis acid-base adduct. 
C) (C2H5)2O is a Lewis acid-base adduct,BF3 is a Lewis acid,and (C2H5)2O:BF3 is a Lewis base. 
D) (C2H5)2O is a Lewis base,BF3 is a Lewis acid-base adduct,and (C2H5)2O:BF3 is a Lewis acid adduct. 
E) (C2H5)2O and BF3 are both Lewis acid-base adducts and (C2H5)2O:BF3 is a Lewis acid.

Question 19

The acid-dissociation constant of hydrocyanic acid (HCN)at 25.0 °C is 4.9 × $10 ^ { - 10 }$ .What is the pH of an aqueous solution of 0.87 mol L-1 sodium cyanide (NaCN)?

Accepted Answer

A) 0.06 
B) 13.94 
C) 4.2 × 10-3 
D) 2.38 
E) 11.62 
A) 0.06 
B) 13.94 
C) 4.2 × 10-3 
D) 2.38 
E) 11.62

Question 20

Identify the triprotic acid.

Accepted Answer

A) HNO3 
B) H3PO4 
C) H2SO3 
D) HClO4 
E) H2SO4 
A) HNO3 
B) H3PO4 
C) H2SO3 
D) HClO4 
E) H2SO4

Exam 15: Acids and Bases

What is the pH of pure water at 40.0 °C if the Kw at this temperature is 2.92 × 10-14?

Which of the following is a weak acid?

Determine the Ka for CH3NH3+ at 25 °C.The Kb for CH3NH2 is 4.4 × 10-4.

Which of the following is a strong acid?

Which one of the following salts,when dissolved in water,produces the solution with a pH closest to 7.00?

Determine the [OH-] concentration of a 0.116 mol L-1 Ba(OH)2 solution at 25 °C.

Which one of the following salts,when dissolved in water,produces the solution with the highest pH?

What is the autoionization of water?

Calculate the pH of a solution that contains 3.9 × 10-4 mol L-1 H3O+ at 25 °C.

Which of the following acids is the strongest? The acid is followed by its Ka value.

Determine the pOH of a 0.188 mol L-1 NH3 solution at 25 °C.The Kb of NH3 is 1.76 × 10-5.

Identify the diprotic acid.

Calculate the hydroxide ion concentration in an aqueous solution with a pH of 4.33 at 25 °C.

Calculate the concentration of H3O+ in a solution that contains 5.5 × 10-5 mol L-1 OH- at 25 °C.Also identify the solution as acidic,basic,or neutral.

Calculate the concentration of bicarbonate ion,HCO3-,in a 0.010 mol L-1 H2CO3 solution that has the stepwise dissociation constants Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11.

What is the hydroxide ion concentration and the pH for a hydrochloric acid solution that has a hydronium ion concentration of 1.50×10−2 mol L−1?1.50 \times 10 ^{- 2 }\mathrm {~mol} \mathrm {~L}^{ - 1 }?1.50×10−2 mol L−1?

Identify the Lewis acid,Lewis base,and Lewis acid-base adduct in the following equation: (C2H5)2O + BF3 ⇌ (C2H5)2O:BF3

The acid-dissociation constant of hydrocyanic acid (HCN)at 25.0 °C is 4.9 × 10−1010 ^ { - 10 }10−10 .What is the pH of an aqueous solution of 0.87 mol L-1 sodium cyanide (NaCN)?

Identify the triprotic acid.

Units of Measurement for Physical and Chemical Change

Atoms and Elements

Molecules,compounds,and Nomenclature

Chemical Reactions and Stoichiometry

Gases

Thermochemistry

The Quantum-Mechanical Model of the Atom

Periodic Properties of the Elements

Chemical Bonding I: Lewis Theory

Chemical Bonding II: Molecular Shapes, valence Bond Theory, and Molecular Orbital Theory

Liquids, solids, and Intermolecular Forces

Solutions

Chemical Kinetics

Chemical Equilibrium

Aqueous Ionic Equilibrium

Gibbs Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry I: Structures

Organic Chemistry II: Reactions

Biochemistry

Chemistry of the Nonmetals

Metals and Metallurgy

Transition Metals and Coordination Compounds

Filters

What is the pH of pure water at 40.0 °C if the K_w at this temperature is 2.92 × 10^-14?

Determine the K_a for CH₃NH₃⁺ at 25 °C.The K_b for CH₃NH₂ is 4.4 × 10^-4.

Determine the [OH^-] concentration of a 0.116 mol L^-¹ Ba(OH)₂ solution at 25 °C.

Calculate the pH of a solution that contains 3.9 × 10^-4 mol L^-1 H₃O⁺ at 25 °C.

Which of the following acids is the strongest? The acid is followed by its K_a value.

Determine the pOH of a 0.188 mol L^-1 NH₃ solution at 25 °C.The K_bof NH₃ is 1.76 × 10^-5.

Calculate the concentration of H₃O⁺ in a solution that contains 5.5 × 10^-5 mol L^-1 OH^- at 25 °C.Also identify the solution as acidic,basic,or neutral.

Calculate the concentration of bicarbonate ion,HCO₃^-,in a 0.010 mol L^-1 H₂CO₃ solution that has the stepwise dissociation constants K_a1 = 4.3 × 10^-7 and K_a2 = 5.6 × 10^-1¹.

What is the hydroxide ion concentration and the pH for a hydrochloric acid solution that has a hydronium ion concentration of $1.50 \times 10 ^{- 2 }\mathrm {~mol} \mathrm {~L}^{ - 1 }?$

Identify the Lewis acid,Lewis base,and Lewis acid-base adduct in the following equation: (C₂H₅)₂O + BF₃ ⇌ (C₂H₅)₂O:BF₃

The acid-dissociation constant of hydrocyanic acid (HCN)at 25.0 °C is 4.9 × $10 ^ { - 10 }$ .What is the pH of an aqueous solution of 0.87 mol L^-1 sodium cyanide (NaCN)?