Chapter 15, Problem 21P

Interpretation Introduction

(a)

Interpretation:

Chalk should be classified as chiral or achiral.

Concept Introduction:

Chirality is the presence of an asymmetric carbon center in a molecule and a molecule which contains a chiral center cannot superimpose on its mirror image. To consider as chiral, molecule or object and its mirror image should not superimpose. To consider as achiral, molecule or object and its mirror image should be superimposed with each other.

In the above diagram, where C is the chiral center/ asymmetric carbon center.

A, B, D, E are four different functional groups.

Answer to Problem 21P

Chalk is achiral.

Explanation of Solution

To consider as chiral, molecule or object and its mirror image should not superimpose. To consider as achiral, molecule or object and its mirror image should be superimposed with each other. The mirror image of chalk is identical and is superimposable on their mirror images. Though they have not sharpened edges, the object and its mirror images are superimposable with each other. Thus, chalk is achiral.

Interpretation Introduction

(b)

Interpretation:

Pair of shoes should be classified as chiral or achiral.

Concept Introduction:

Chirality is the presence of an asymmetric carbon center in a molecule and a molecule which contains a chiral center cannot superimpose on its mirror image. To consider as chiral, molecule or object and its mirror image should not superimpose. To consider as achiral, molecule or object and its mirror image should be superimposed with each other.

In the above diagram, where C is the chiral center/ asymmetric carbon center.

A, B, D, E are four different functional groups.

Answer to Problem 21P

Pair of shoes are chiral.

Explanation of Solution

To consider as chiral, molecule or object and its mirror image should not superimpose. To consider as achiral, molecule or object and its mirror image should be superimposed with each other. The mirror image of pair of shoes arenot identical and not superimposable. The object and its mirror images are not superimposable with each otherand not align all the parts of the objects with its mirror image. Thus, pair of shoes are chiral.

Interpretation Introduction

(c)

Interpretation:

A football should be classified as chiral or achiral.

Concept Introduction:

Chirality is the presence of an asymmetric carbon center in a molecule and a molecule which contains a chiral center cannot superimpose on its mirror image. To consider as chiral, molecule or object and its mirror image should not superimpose. To consider as achiral, molecule or object and its mirror image should be superimposed with each other.

In the above diagram, where C is the chiral center/ asymmetric carbon center.

A, B, D, E are four different functional groups.

Answer to Problem 21P

Football is achiral.

Explanation of Solution

To be considered as chiral, molecule or object and its mirror image should not superimpose. To consider as achiral, molecule or object and its mirror image should be superimposed with each other. The mirror image of a football is identical and superimposable. The object and its mirror images are superimposable with each other. Thus, football is achiral.