Question 1

Which one of the following salts forms aqueous solutions with pH F1F1F1S1F1F1F10 7?

Accepted Answer

A) Na2S 
B) NaCl 
C) NaClO2 
D) NaNO2 
E) Na2CO3 
A) Na2S 
B) NaCl 
C) NaClO2 
D) NaNO2 
E) Na2CO3

Question 2

Phosphoric acid is a triprotic acid, ionizing in the following sequential steps: H3PO4 F1F1F1S1F1F1F10 H2O   H2PO4F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10   H2PO4F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   HPO42F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10    
HPO42F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   PO43F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10   Which equilibrium is most important in determining the pH of a solution of sodium phosphate?

Accepted Answer

A) HPO42F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   PO43F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10 
B) H3PO4 F1F1F1S1F1F1F10 H2O   H2PO4F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10 
C) PO43F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   HPO42F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10 
D) H2PO4F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   H3PO4 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10 
E) 2H2O   H3OF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10 
A) HPO42F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   PO43F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10 
B) H3PO4 F1F1F1S1F1F1F10 H2O   H2PO4F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H3OF1F1F1S1F1F1F10 
C) PO43F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   HPO42F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10 
D) H2PO4F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 H2O   H3PO4 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10 
E) 2H2O   H3OF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 OHF1F1F1S1F1F1F10

Question 3

Which of the following groups, A-D, consist of salts that all form basic solutions in water? (Ac F1F1F1S1F1F1F10 acetate)

Accepted Answer

A) NaNO3, NH4CN, NaAc, NH4Cl 
B) Na2CO3, KCl, NaOOCH3, NH4Cl 
C) Na2CO3, NaF, NaOOCH3, NaCN 
D) NaHCO3, NaF, NH4Cl, Na2SO3 
E) none or all of the above 
A) NaNO3, NH4CN, NaAc, NH4Cl 
B) Na2CO3, KCl, NaOOCH3, NH4Cl 
C) Na2CO3, NaF, NaOOCH3, NaCN 
D) NaHCO3, NaF, NH4Cl, Na2SO3 
E) none or all of the above

Question 4

Which one of the following is not a strong acid?

Accepted Answer

A) nitric acid, HNO3 
B) sulfuric acid, H2SO4 
C) carbonic acid, H2CO3 
D) hydrochloric acid, HCl 
E) perchloric acid, HClO4 
A) nitric acid, HNO3 
B) sulfuric acid, H2SO4 
C) carbonic acid, H2CO3 
D) hydrochloric acid, HCl 
E) perchloric acid, HClO4

Question 5

The concentration of acetic acid (pKa F1F1F1S1F1F1F10 4.75) in vinegar is about 1.0 M. With this information, what do you predict the pH of vinegar to be?

Accepted Answer

A) 4.75 
B) 2.4 
C) 4.0 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 
D) 7.0 
E) 5.35 
A) 4.75 
B) 2.4 
C) 4.0 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 
D) 7.0 
E) 5.35

Question 6

A cleaning solution has a pOH of 4.0. What are the pH and hydronium ion concentration of this solution?

Accepted Answer

pH F1F1F1S1F1F1F10

Question 7

Which expression defines the autoionization constant for water, Kw?

Accepted Answer

A) [H3OF1F1F1S1F1F1F10][OHF1F1F1S1F1F1F10] 
B) [H2O][H3OF1F1F1S1F1F1F10] 
C) [OHF1F1F1S1F1F1F10][H2O] 
D) [H4O2F1F1F1S1F1F1F10][O2F1F1F1S1F1F1F10] 
E) [H2O][H2O] 
A) [H3OF1F1F1S1F1F1F10][OHF1F1F1S1F1F1F10] 
B) [H2O][H3OF1F1F1S1F1F1F10] 
C) [OHF1F1F1S1F1F1F10][H2O] 
D) [H4O2F1F1F1S1F1F1F10][O2F1F1F1S1F1F1F10] 
E) [H2O][H2O]

Question 8

In the following reaction in aqueous solution, the acid reactant is ________ and its conjugate base product is ________. CH3NH2 F1F1F1S1F1F1F10 HSO4F1F1F1S1F1F1F10   CH3NH3F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 SO42F1F1F1S1F1F1F10

Accepted Answer

A) CH3NH2; CH3NH3F1F1F1S1F1F1F10 
B) CH3NH2; SO42F1F1F1S1F1F1F10 
C) HSO4F1F1F1S1F1F1F10; CH3NH3F1F1F1S1F1F1F10 
D) HSO4F1F1F1S1F1F1F10; SO42F1F1F1S1F1F1F10 
E) HSO4F1F1F1S1F1F1F10; H3OF1F1F1S1F1F1F10 
A) CH3NH2; CH3NH3F1F1F1S1F1F1F10 
B) CH3NH2; SO42F1F1F1S1F1F1F10 
C) HSO4F1F1F1S1F1F1F10; CH3NH3F1F1F1S1F1F1F10 
D) HSO4F1F1F1S1F1F1F10; SO42F1F1F1S1F1F1F10 
E) HSO4F1F1F1S1F1F1F10; H3OF1F1F1S1F1F1F10

Question 9

In the following reaction in aqueous solution, the base reactant is ________ and its conjugate acid product is ________. HCOOH F1F1F1S1F1F1F10 C5H5N   HCOOF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 C5H5NHF1F1F1S1F1F1F10

Accepted Answer

A) HCOOH; HCOOF1F1F1S1F1F1F10 
B) C5H5N; HCOOF1F1F1S1F1F1F10 
C) HCOOH; C5H5NHF1F1F1S1F1F1F10 
D) C5H5N; C5H5NHF1F1F1S1F1F1F10 
E) C5H5N; OHF1F1F1S1F1F1F10 
A) HCOOH; HCOOF1F1F1S1F1F1F10 
B) C5H5N; HCOOF1F1F1S1F1F1F10 
C) HCOOH; C5H5NHF1F1F1S1F1F1F10 
D) C5H5N; C5H5NHF1F1F1S1F1F1F10 
E) C5H5N; OHF1F1F1S1F1F1F10

Question 10

The pH of an aqueous sodium fluoride (NaF) solution is ________ because ________.

Accepted Answer

A) 7; sodium fluoride is a simple salt 
B) above 7; fluoride is a weak base 
C) below 7; fluoride reacts with water to make hydrofluoric acid 
D) about 7; fluoride is a weak base, but produces hydrofluoric acid, and these two neutralize one another 
E) 0; sodium fluoride is a salt, not an acid or a base 
A) 7; sodium fluoride is a simple salt 
B) above 7; fluoride is a weak base 
C) below 7; fluoride reacts with water to make hydrofluoric acid 
D) about 7; fluoride is a weak base, but produces hydrofluoric acid, and these two neutralize one another 
E) 0; sodium fluoride is a salt, not an acid or a base

Question 11

What is the pH of a 0.055 M solution of sodium cyanide? The Ka value for hydrocyanic acid is 6.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1010.

Accepted Answer

Question 12

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. HClO, HClO2, HClO3

Accepted Answer

A) HClO F1F1F1S1F1F1F10 HClO2 
B) HClO F1F1F1S1F1F1F10 HClO3 
C) HClO2 F1F1F1S1F1F1F10 HClO3 
D) HClO2 F1F1F1S1F1F1F10 HClO 
E) HClO3 F1F1F1S1F1F1F10 HClO 
A) HClO F1F1F1S1F1F1F10 HClO2 
B) HClO F1F1F1S1F1F1F10 HClO3 
C) HClO2 F1F1F1S1F1F1F10 HClO3 
D) HClO2 F1F1F1S1F1F1F10 HClO 
E) HClO3 F1F1F1S1F1F1F10 HClO

Question 13

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. HOCl, HOBr, HOI

Accepted Answer

A) HOBr F1F1F1S1F1F1F10 HOCl 
B) HOBr F1F1F1S1F1F1F10 HOI 
C) HOCl F1F1F1S1F1F1F10 HOBr 
D) HOCl F1F1F1S1F1F1F10 HOI 
E) HOI F1F1F1S1F1F1F10 HOCl 
A) HOBr F1F1F1S1F1F1F10 HOCl 
B) HOBr F1F1F1S1F1F1F10 HOI 
C) HOCl F1F1F1S1F1F1F10 HOBr 
D) HOCl F1F1F1S1F1F1F10 HOI 
E) HOI F1F1F1S1F1F1F10 HOCl

Question 14

Formic acid is a weak acid naturally occurring in certain species of ants. Calculate the acid ionization constant for formic acid if a 0.213 M solution is 2.86% ionized. The abbreviated structural formula for formic acid is HCOOH.

Accepted Answer

A) 7.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 
B) 6.4 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 
C) 1.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 
D) 1.9 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 
E) 3.5 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F108 
A) 7.2 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 
B) 6.4 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 
C) 1.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 
D) 1.9 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 
E) 3.5 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F108

Question 15

Which of the following salts produce(s) a neutral solution when dissolved in water? KF
Mg(NO2)2
NaClO4
CaCO3

Accepted Answer

A) I only 
B) II only 
C) III only 
D) II and III only 
E) I and IV only 
A) I only 
B) II only 
C) III only 
D) II and III only 
E) I and IV only

Question 16

Which one of the following is a conjugate acid-base pair?

Accepted Answer

A) NH3 and NH4F1F1F1S1F1F1F10 
B) H3OF1F1F1S1F1F1F10 and OHF1F1F1S1F1F1F10 
C) NH2F1F1F1S1F1F1F10 and NH4F1F1F1S1F1F1F10 
D) H2O and O2F1F1F1S1F1F1F10 
E) NaF and FF1F1F1S1F1F1F10 
A) NH3 and NH4F1F1F1S1F1F1F10 
B) H3OF1F1F1S1F1F1F10 and OHF1F1F1S1F1F1F10 
C) NH2F1F1F1S1F1F1F10 and NH4F1F1F1S1F1F1F10 
D) H2O and O2F1F1F1S1F1F1F10 
E) NaF and FF1F1F1S1F1F1F10

Question 17

What is the pH of a 0.25 M NH4Cl solution (Ka F1F1F1S1F1F1F10 5.68 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1010)?

Accepted Answer

Question 18

A 0.100 M solution of a monoprotic weak acid has a pH of 3.00. What is the pKa of this acid?

Accepted Answer

A) 5.00 
B) 0.999 
C) 3.00 
D) 9.99 
E) 6.00 
A) 5.00 
B) 0.999 
C) 3.00 
D) 9.99 
E) 6.00

Question 19

Which one of the following is not a conjugate acid-base pair?

Accepted Answer

A) NH3 and NH2F1F1F1S1F1F1F10 
B) HNO3 and HNO2 
C) HI and IF1F1F1S1F1F1F10 
D) H2PO4F1F1F1S1F1F1F10 and HPO42F1F1F1S1F1F1F10 
E) H2O and OHF1F1F1S1F1F1F10 
A) NH3 and NH2F1F1F1S1F1F1F10 
B) HNO3 and HNO2 
C) HI and IF1F1F1S1F1F1F10 
D) H2PO4F1F1F1S1F1F1F10 and HPO42F1F1F1S1F1F1F10 
E) H2O and OHF1F1F1S1F1F1F10

Question 20

What is the actual concentration of the molecular form of HF in a 1.0 M HF solution given that Ka of HF is 6.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104?

Accepted Answer

A) 2.6 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F102 M 
B) 0.97 M 
C) 1.59 M 
D) 6.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 M 
E) 1.0 M 
A) 2.6 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F102 M 
B) 0.97 M 
C) 1.59 M 
D) 6.8 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F104 M 
E) 1.0 M

Exam 15: Acidbase Equilibria: Proton Transfer in Biological Systems

Which one of the following salts forms aqueous solutions with pH  7?

Phosphoric acid is a triprotic acid, ionizing in the following sequential steps: H3PO4  H2O H2PO4  H3O H2PO4  H2O HPO42  H3O HPO42  H2O PO43  H3O Which equilibrium is most important in determining the pH of a solution of sodium phosphate?

Which of the following groups, A-D, consist of salts that all form basic solutions in water? (Ac  acetate)

Which one of the following is not a strong acid?

The concentration of acetic acid (pKa  4.75) in vinegar is about 1.0 M. With this information, what do you predict the pH of vinegar to be?

A cleaning solution has a pOH of 4.0. What are the pH and hydronium ion concentration of this solution?

Which expression defines the autoionization constant for water, Kw?

In the following reaction in aqueous solution, the acid reactant is ________ and its conjugate base product is ________. CH3NH2  HSO4 CH3NH3  SO42

In the following reaction in aqueous solution, the base reactant is ________ and its conjugate acid product is ________. HCOOH  C5H5N HCOO  C5H5NH

The pH of an aqueous sodium fluoride (NaF) solution is ________ because ________.

What is the pH of a 0.055 M solution of sodium cyanide? The Ka value for hydrocyanic acid is 6.2  1010.

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. HClO, HClO2, HClO3

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. HOCl, HOBr, HOI

Formic acid is a weak acid naturally occurring in certain species of ants. Calculate the acid ionization constant for formic acid if a 0.213 M solution is 2.86% ionized. The abbreviated structural formula for formic acid is HCOOH.

Which of the following salts produce(s) a neutral solution when dissolved in water? KF Mg(NO2)2 NaClO4 CaCO3

Which one of the following is a conjugate acid-base pair?

What is the pH of a 0.25 M NH4Cl solution (Ka  5.68  1010)?

A 0.100 M solution of a monoprotic weak acid has a pH of 3.00. What is the pKa of this acid?

Which one of the following is not a conjugate acid-base pair?

What is the actual concentration of the molecular form of HF in a 1.0 M HF solution given that Ka of HF is 6.8  104?

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: The Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Crystals, Alloys, and Polymers

Chemical Kinetics: Reactions in the Atmosphere

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Additional Aqueous Equilibria: Chemistry and the Oceans

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: The Quest for Clean Energy

Nuclear Chemistry: Applications to Energy and Medicine

Organic and Biological Molecules: the Compounds of Life

The Main Group Elements: Life and the Periodic Table

Transition Metals: Biological and Medical Applications

Filters

The concentration of acetic acid (pK_a  4.75) in vinegar is about 1.0 M. With this information, what do you predict the pH of vinegar to be?

Which expression defines the autoionization constant for water, K_w?

In the following reaction in aqueous solution, the acid reactant is and its conjugate base product is . CH₃NH₂  HSO₄^ CH₃NH₃^  SO₄²^

In the following reaction in aqueous solution, the base reactant is and its conjugate acid product is . HCOOH  C₅H₅N HCOO^  C₅H₅NH^

The pH of an aqueous sodium fluoride (NaF) solution is because .

What is the pH of a 0.055 M solution of sodium cyanide? The K_a value for hydrocyanic acid is 6.2  10^¹⁰.

Identify the weakest and strongest acids in the group below. The weakest acid is listed first in the responses. HClO, HClO₂, HClO₃

Which of the following salts produce(s) a neutral solution when dissolved in water? KF Mg(NO₂)₂ NaClO₄ CaCO₃

What is the pH of a 0.25 M NH₄Cl solution (K_a  5.68  10^¹⁰)?

A 0.100 M solution of a monoprotic weak acid has a pH of 3.00. What is the pK_a of this acid?

What is the actual concentration of the molecular form of HF in a 1.0 M HF solution given that K_a of HF is 6.8  10^⁴?