ORGANIC CHEMISTRY-PRINT COMPANION (LL)
ORGANIC CHEMISTRY-PRINT COMPANION (LL)
3rd Edition
ISBN: 9781119444251
Author: Klein
Publisher: WILEY
Question
Book Icon
Chapter 21, Problem 47PP

(a)

Interpretation Introduction

Interpretation:

To identify which of the given set of compounds have pKa value lesser than 20 and to identify the acidic proton in the same

Concept introduction:

pKa is negative base-10 logarithm of the dissociation constant of acid (Ka) of a solution. pKa= -log10Ka pKa value of acid is inversely related to the strength of acid.  If pKa value is lower it means the acid is stronger and vice-versa.

pKa is used is to describe acid dissociation because it is expressed in small decimal numbers.

If pKa value is below 20 the compound is said to have acidic proton and vice versa

To identify : The compound pKa value and the most acidic proton

ORGANIC CHEMISTRY-PRINT COMPANION (LL), Chapter 21, Problem 47PP , additional homework tip  1

(a)

Expert Solution
Check Mark

Answer to Problem 47PP

The pKa value of (a) is just below 20 and it has acidic proton next to carbonyl

Explanation of Solution

Deprotonation of the highlighted hydrogen and resonance stabilization

ORGANIC CHEMISTRY-PRINT COMPANION (LL), Chapter 21, Problem 47PP , additional homework tip  2

 From the above scheme we can infer that the highlighted hydrogen is removed resulting in formation of a conjugate base.  The conjugate base is resonance stabilized as the negative charge is delocalized on oxygen atom also.  Therefore the highlighted proton is most acidic (pKa value below 20) as the removal of it leads to a stabilized conjugate base.

(b)

Interpretation Introduction

Interpretation:

To identify which of the given set of compounds have pKa value lesser than 20 and to identify the acidic proton in the same

Concept introduction:

pKa is negative base-10 logarithm of the dissociation constant of acid (Ka) of a solution. pKa= -log10Ka pKa value of acid is inversely related to the strength of acid.  If pKa value is lower it means the acid is stronger and vice-versa.

pKa is used is to describe acid dissociation because it is expressed in small decimal numbers.

If pKa value is below 20 the compound is said to have acidic proton and vice versa

To identify : The compound pKa value and the most acidic proton

ORGANIC CHEMISTRY-PRINT COMPANION (LL), Chapter 21, Problem 47PP , additional homework tip  3

(b)

Expert Solution
Check Mark

Answer to Problem 47PP

The pKa value of (b) is just above 20 and it does not have acidic proton

No acidic proton is present

Explanation of Solution

The above given compound does not have an acidic proton that can undergo deprotonation.  Hence this compound is expected to have pKa above 20.

(c)

Interpretation Introduction

Interpretation:

To identify which of the given set of compounds have pKa value lesser than 20 and to identify the acidic proton in the same

Concept introduction:

pKa is negative base-10 logarithm of the dissociation constant of acid (Ka) of a solution. pKa= -log10Ka pKa value of acid is inversely related to the strength of acid.  If pKa value is lower it means the acid is stronger and vice-versa.

pKa is used is to describe acid dissociation because it is expressed in small decimal numbers.

If pKa value is below 20 the compound is said to have acidic proton and vice versa

To identify : The compound pKa value and the most acidic proton

ORGANIC CHEMISTRY-PRINT COMPANION (LL), Chapter 21, Problem 47PP , additional homework tip  4

(c)

Expert Solution
Check Mark

Answer to Problem 47PP

The pKa value of (c) is just below 20 and it has acidic proton next to carbonyl

Explanation of Solution

Deprotonation of the highlighted hydrogen and resonance stabilization

ORGANIC CHEMISTRY-PRINT COMPANION (LL), Chapter 21, Problem 47PP , additional homework tip  5

From the above scheme we can infer that the highlighted hydrogen is removed resulting in formation of a conjugate base.  The conjugate base is resonance stabilized as the negative charge is delocalized on oxygen atom also.  Therefore the highlighted proton is most acidic (pKa value below 20) as the removal of it leads to a stabilized conjugate base.

(d)

Interpretation Introduction

Interpretation:

To identify which of the given set of compounds have pKa value lesser than 20 and to identify the acidic proton in the same

Concept introduction:

pKa is negative base-10 logarithm of the dissociation constant of acid (Ka) of a solution. pKa= -log10Ka pKa value of acid is inversely related to the strength of acid.  If pKa value is lower it means the acid is stronger and vice-versa.

pKa is used is to describe acid dissociation because it is expressed in small decimal numbers.

If pKa value is below 20 the compound is said to have acidic proton and vice versa

To identify : The compound pKa value and the most acidic proton

ORGANIC CHEMISTRY-PRINT COMPANION (LL), Chapter 21, Problem 47PP , additional homework tip  6

(d)

Expert Solution
Check Mark

Answer to Problem 47PP

The pKa value of (d) is just below 20 and it has acidic proton next to carbonyl

Explanation of Solution

Deprotonation of the highlighted hydrogen and resonance stabilization

ORGANIC CHEMISTRY-PRINT COMPANION (LL), Chapter 21, Problem 47PP , additional homework tip  7

From the above scheme we can infer that the highlighted hydrogen is removed resulting in formation of a conjugate base.  The conjugate base is resonance stabilized as the negative charge is delocalized on two oxygen atoms (doubly stabilized enolate ion).  Therefore the highlighted proton is most acidic (pKa value below 20) as the removal of it leads to a stabilized conjugate base.

(e)

Interpretation Introduction

Interpretation:

To identify which of the given set of compounds have pKa value lesser than 20 and to identify the acidic proton in the same

Concept introduction:

pKa is negative base-10 logarithm of the dissociation constant of acid (Ka) of a solution. pKa= -log10Ka pKa value of acid is inversely related to the strength of acid.  If pKa value is lower it means the acid is stronger and vice-versa.

pKa is used is to describe acid dissociation because it is expressed in small decimal numbers.

If pKa value is below 20 the compound is said to have acidic proton and vice versa

To identify : The compound pKa value and the most acidic proton

ORGANIC CHEMISTRY-PRINT COMPANION (LL), Chapter 21, Problem 47PP , additional homework tip  8

(e)

Expert Solution
Check Mark

Answer to Problem 47PP

The pKa value of (e) is just below 20 and it has acidic proton next to carbonyl

Explanation of Solution

Deprotonation of the highlighted hydrogen

ORGANIC CHEMISTRY-PRINT COMPANION (LL), Chapter 21, Problem 47PP , additional homework tip  9

From the above scheme we can infer that the highlighted hydrogen is removed resulting in formation of an alokoxide ion.  As such the compound is expected to have pKa lower than 20.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Chapter 21 Solutions

ORGANIC CHEMISTRY-PRINT COMPANION (LL)

Ch. 21.2 - Prob. 10CCCh. 21.2 - Prob. 11CCCh. 21.2 - Prob. 12CCCh. 21.2 - Prob. 13CCCh. 21.3 - Prob. 2LTSCh. 21.3 - Prob. 14PTSCh. 21.3 - Prob. 15PTSCh. 21.3 - Prob. 16ATSCh. 21.3 - Prob. 3LTSCh. 21.3 - Prob. 17PTSCh. 21.3 - Prob. 18ATSCh. 21.3 - Prob. 4LTSCh. 21.3 - Prob. 19PTSCh. 21.3 - Prob. 20ATSCh. 21.3 - Prob. 21CCCh. 21.3 - Prob. 22CCCh. 21.3 - Prob. 23CCCh. 21.4 - Prob. 24CCCh. 21.4 - Prob. 25CCCh. 21.4 - Prob. 26CCCh. 21.4 - Prob. 27CCCh. 21.4 - Prob. 28CCCh. 21.5 - Prob. 29CCCh. 21.5 - Prob. 30CCCh. 21.5 - Prob. 5LTSCh. 21.5 - Prob. 31PTSCh. 21.5 - Prob. 32ATSCh. 21.5 - Prob. 6LTSCh. 21.5 - Prob. 33PTSCh. 21.5 - Prob. 34ATSCh. 21.6 - Prob. 35CCCh. 21.6 - Prob. 36CCCh. 21.6 - Prob. 37CCCh. 21.6 - Prob. 7LTSCh. 21.6 - Prob. 38PTSCh. 21.6 - Prob. 39ATSCh. 21.6 - Prob. 40CCCh. 21.6 - Prob. 41CCCh. 21.7 - Prob. 8LTSCh. 21.7 - Prob. 42PTSCh. 21.7 - Prob. 43PTSCh. 21.7 - Prob. 9LTSCh. 21.7 - Prob. 45PTSCh. 21.7 - Prob. 46ATSCh. 21 - Prob. 47PPCh. 21 - Prob. 48PPCh. 21 - Prob. 49PPCh. 21 - Prob. 50PPCh. 21 - Prob. 51PPCh. 21 - Prob. 52PPCh. 21 - Prob. 53PPCh. 21 - Prob. 54PPCh. 21 - Prob. 55PPCh. 21 - Prob. 56PPCh. 21 - Prob. 57PPCh. 21 - Prob. 58PPCh. 21 - Prob. 59PPCh. 21 - Prob. 60PPCh. 21 - Prob. 61PPCh. 21 - Prob. 62PPCh. 21 - Prob. 63PPCh. 21 - Prob. 64PPCh. 21 - Prob. 65PPCh. 21 - Prob. 66PPCh. 21 - Prob. 67PPCh. 21 - Prob. 68PPCh. 21 - Prob. 69PPCh. 21 - Prob. 70PPCh. 21 - Prob. 71PPCh. 21 - Prob. 72PPCh. 21 - Prob. 73PPCh. 21 - Prob. 74PPCh. 21 - Prob. 75PPCh. 21 - Prob. 76PPCh. 21 - Prob. 77PPCh. 21 - Prob. 78PPCh. 21 - Prob. 79PPCh. 21 - Prob. 80PPCh. 21 - Prob. 81PPCh. 21 - Prob. 82PPCh. 21 - Prob. 83PPCh. 21 - Prob. 84PPCh. 21 - Prob. 85PPCh. 21 - Prob. 86PPCh. 21 - Prob. 87PPCh. 21 - Prob. 88PPCh. 21 - Prob. 89IPCh. 21 - Prob. 90IPCh. 21 - Prob. 91IPCh. 21 - Prob. 92IPCh. 21 - Prob. 93IPCh. 21 - Prob. 94IPCh. 21 - Prob. 95IPCh. 21 - Prob. 96IPCh. 21 - Prob. 97IPCh. 21 - Prob. 98IPCh. 21 - Prob. 99IPCh. 21 - Prob. 100IPCh. 21 - Prob. 101IPCh. 21 - Prob. 102IPCh. 21 - Prob. 103IPCh. 21 - Prob. 104IPCh. 21 - Prob. 105IPCh. 21 - Prob. 106IPCh. 21 - Prob. 107IPCh. 21 - Prob. 108IPCh. 21 - Prob. 109IPCh. 21 - Prob. 110IPCh. 21 - Prob. 111IPCh. 21 - Prob. 112IPCh. 21 - Prob. 113IPCh. 21 - Prob. 114IPCh. 21 - Prob. 115IPCh. 21 - Prob. 116CPCh. 21 - Prob. 117CPCh. 21 - Prob. 118CP
Knowledge Booster
Background pattern image
Recommended textbooks for you
Text book image
Chemistry
Chemistry
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Cengage Learning
Text book image
Chemistry
Chemistry
ISBN:9781259911156
Author:Raymond Chang Dr., Jason Overby Professor
Publisher:McGraw-Hill Education
Text book image
Principles of Instrumental Analysis
Chemistry
ISBN:9781305577213
Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:Cengage Learning
Text book image
Organic Chemistry
Chemistry
ISBN:9780078021558
Author:Janice Gorzynski Smith Dr.
Publisher:McGraw-Hill Education
Text book image
Chemistry: Principles and Reactions
Chemistry
ISBN:9781305079373
Author:William L. Masterton, Cecile N. Hurley
Publisher:Cengage Learning
Text book image
Elementary Principles of Chemical Processes, Bind...
Chemistry
ISBN:9781118431221
Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:WILEY