Question 1

Provide a brief explanation, based on features of the molecules, for the following trend in pKa values?

Accepted Answer

This trend is best understood in terms o

Question 2

Which of the following anions is the strongest base?

Accepted Answer

A)  CH3COO- 
B)  HO- 
C)  NH2- 
D)  Cl- 
A)  CH3COO- 
B)  HO- 
C)  NH2- 
D)  Cl-

Question 3

Which of the following is the strongest acid?

Accepted Answer

A)  CH3OH 
B)  CH3CHO 
C)  CH3COCH3 
D)  CH3COOH 
A)  CH3OH 
B)  CH3CHO 
C)  CH3COCH3 
D)  CH3COOH

Question 4

Which of the following equations is correct?

Accepted Answer

A)  DG$\degree$ = DH$\degree$ - TDS$\degree$ 
B)  DH$\degree$ = DG$\degree$ - TDS$\degree$ 
C)  DG$\degree$ = DH$\degree$ - DS$\degree$ 
D)  DG$\degree$ = DH$\degree$ - DS$\degree$/T 
A)  DG$\degree$ = DH$\degree$ - TDS$\degree$ 
B)  DH$\degree$ = DG$\degree$ - TDS$\degree$ 
C)  DG$\degree$ = DH$\degree$ - DS$\degree$ 
D)  DG$\degree$ = DH$\degree$ - DS$\degree$/T

Question 5

Which of the following terms describes the role of ethyne in the acid-base reaction shown?

Accepted Answer

A)  Brønsted-Lowry acid 
B)  Brønsted-Lowry base 
C)  Lewis acid 
D)  Lewis base 
A)  Brønsted-Lowry acid 
B)  Brønsted-Lowry base 
C)  Lewis acid 
D)  Lewis base

Question 6

What is the approximate pKa value of HCl?

Accepted Answer

A)  -7 
B)  5 
C)  16 
D)  51 
A)  -7 
B)  5 
C)  16 
D)  51

Question 7

Which of the following compounds has the highest pKa?

Accepted Answer

A)  SiH4 
B)  H2S 
C)  PH3 
D)  HCl 
A)  SiH4 
B)  H2S 
C)  PH3 
D)  HCl

Question 8

What is the value of the equilibrium constant, Keq, for the following reaction?

Accepted Answer

A)  1013 
B)  10-13 
C)  13 
D)  (1/13) 
A)  1013 
B)  10-13 
C)  13 
D)  (1/13)

Question 9

What is the value of the equilibrium constant for the following equilibrium?

Accepted Answer

log₁₀K_eq = pK_a(acid) - pK

Question 10

Provide the equation that relates the equilibrium constant, Keq, to the acid dissociation constant, Ka, for the following equilibrium.

Accepted Answer

Question 11

Which of the following compounds has the highest pKa?

Accepted Answer

A)  NH3 
B)  H2O 
C)  HCl 
D)  CH4 
A)  NH3 
B)  H2O 
C)  HCl 
D)  CH4

Question 12

Which of the following is a definition of the rate-determining step of a reaction mechanism?

Accepted Answer

A)  the first step 
B)  the last step 
C)  the step that crosses the highest energy barrier 
D)  the most exothermic step 
A)  the first step 
B)  the last step 
C)  the step that crosses the highest energy barrier 
D)  the most exothermic step

Question 13

Which of the following has a pKa value of approximately 25?

Accepted Answer

A)  CH3CH3 
B)  CH2=CH2 
C)  HCºCH 
D)  CH3CH2OH 
A)  CH3CH3 
B)  CH2=CH2 
C)  HCºCH 
D)  CH3CH2OH

Question 14

Which of the following is present in the highest concentration upon dissolution of H2SO4 in water?

Accepted Answer

A)  H2SO4 
B)  H+ 
C)  H3O+ 
D)  HO- 
A)  H2SO4 
B)  H+ 
C)  H3O+ 
D)  HO-

Question 15

Which of the following is a Lewis acid but not a Brønsted-Lowry acid?

Accepted Answer

A)  CH3COOH 
B)  AlCl3 
C)  H2O 
D)  CH3OH 
A)  CH3COOH 
B)  AlCl3 
C)  H2O 
D)  CH3OH

Question 16

Which atom in the following structure is preferentially protonated by a strong acid?

Accepted Answer

A)  i 
B)  ii 
C)  iii 
D)  iv 
A)  i 
B)  ii 
C)  iii 
D)  iv

Question 17

Which of the following is a feature of a Brønsted-Lowry acid?

Accepted Answer

A)  proton donor 
B)  proton acceptor 
C)  electron pair donor 
D)  electron pair acceptor 
A)  proton donor 
B)  proton acceptor 
C)  electron pair donor 
D)  electron pair acceptor

Question 18

Provide a brief explanation, based on features of the molecules, for the following trend in pKa values?

Accepted Answer

This trend is best understood in terms o

Question 19

Provide the equation for the acid dissociate constant, Ka,for the following equilibrium.

Accepted Answer

Question 20

Which of the following is the strongest acid?

Accepted Answer

A)  HCl 
B)  HI 
C)  HF 
D)  HBr 
A)  HCl 
B)  HI 
C)  HF 
D)  HBr

Exam 4: Acids and Bases

Provide a brief explanation, based on features of the molecules, for the following trend in pKa values?

Which of the following anions is the strongest base?

Which of the following is the strongest acid?

Which of the following equations is correct?

Which of the following terms describes the role of ethyne in the acid-base reaction shown?

What is the approximate pKa value of HCl?

Which of the following compounds has the highest pKa?

What is the value of the equilibrium constant, Keq, for the following reaction?

What is the value of the equilibrium constant for the following equilibrium?

Provide the equation that relates the equilibrium constant, Keq, to the acid dissociation constant, Ka, for the following equilibrium.

Which of the following compounds has the highest pKa?

Which of the following is a definition of the rate-determining step of a reaction mechanism?

Which of the following has a pKa value of approximately 25?

Which of the following is present in the highest concentration upon dissolution of H2SO4 in water?

Which of the following is a Lewis acid but not a Brønsted-Lowry acid?

Which atom in the following structure is preferentially protonated by a strong acid?

Which of the following is a feature of a Brønsted-Lowry acid?

Provide a brief explanation, based on features of the molecules, for the following trend in pKa values?

Provide the equation for the acid dissociate constant, Ka,for the following equilibrium.

Which of the following is the strongest acid?

Covalent Bonding and Shapes of Molecules

Alkanes and Cycloalkanes

Stereoisomerism and Chirality

Alkenes: Bonding, Nomenclature, and Properties

Reactions of Alkenes

Alkynes

Haloalkanes, Halogenation, and Radical Reactions

Nucleophilic Substitution and Beta-Elimination

Alcohols

Ethers, Epoxides, and Sulfides

Infrared Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

Mass Spectrometry

An Introduction to Organometallic Compounds

Aldehydes and Ketones

Carboxylic Acids

Functional Derivatives of Carboxylic Acids

Enolate Anions and Enamines

Dienes, Conjugated Systems, and Pericyclic Reactions

Benzene and the Concept of Aromaticity

Reactions of Benzene and Its Derivatives

Filters

Provide a brief explanation, based on features of the molecules, for the following trend in pK_a values?

What is the approximate pK_a value of HCl?

Which of the following compounds has the highest pK_a?

What is the value of the equilibrium constant, K_eq, for the following reaction?

Provide the equation that relates the equilibrium constant, K_eq, to the acid dissociation constant, K_a, for the following equilibrium.

Which of the following compounds has the highest pK_a?

Which of the following has a pK_a value of approximately 25?

Which of the following is present in the highest concentration upon dissolution of H₂SO₄ in water?

Provide a brief explanation, based on features of the molecules, for the following trend in pK_a values?

Provide the equation for the acid dissociate constant, K_a,for the following equilibrium.