Chapter U2.2, Problem 7E

Interpretation Introduction

(a)

Interpretation:

The isomer of given compound needs to be drawn.

Concept introduction:

Isomers can be defined as the organic molecules which have the same molecular formula and different structural formula.

Due to different structural formula, isomers have different physical and chemical properties.

Answer to Problem 7E

Explanation of Solution

The formula of the given compound is CH₃CH₂COOH (propanoic acid). Propanoic acid is a carboxylic acid with two carbon atoms and a −COOH as a functional group. The functional isomer of propanoic acid will be methyl ethanoate which is an ester with general chemical formula as RCOOR.

The structure is represented as follows:

Interpretation Introduction

(b)

Interpretation:

The isomer of a given compound needs to be determined.

Concept introduction:

Isomers can be defined as the organic molecules which have the same molecular formula and different structural formula.

Due to different structural formula, isomers have different physical and chemical properties.

Answer to Problem 7E

Explanation of Solution

The given structure is as follows:

There are 5 carbon atoms thus, it is 2-pentanone.

2-pentanone is an isomer of pentanal as it also contains 5 carbon atoms, 1 O atom and 10 H atoms.

The structure of pentanal is represented as follows:

Interpretation Introduction

(c)

Interpretation:

The isomer of a given compound needs to be determined.

Concept introduction:

Isomers can be defined as the organic molecules which have the same molecular formula and different structural formula.

Due to different structural formula, isomers have different physical and chemical properties.

Answer to Problem 7E

Explanation of Solution

The given structure is as follows:

The formula of the given compound is ${\text{CH}}_{\text{3}}{\text{COCH(CH}}_{\text{3}}{\text{)CH}}_{\text{3}}$ (3-methylbutanone).

3-methylbutanone must be an isomer of pentanal as both have the same molecular formula but different structural formulas.

The structure of pentanal is as follows:

Interpretation Introduction

(d)

Interpretation:

The isomer of a given compound needs to be determined.

Concept introduction:

Isomers can be defined as the organic molecules which have the same molecular formula and different structural formula.

Due to different structural formula, isomers have different physical and chemical properties.

Answer to Problem 7E

Explanation of Solution

The given structure is as follows:

The formula of the given compound is ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{COOCH}}_{\text{3}}$ (methylpropanoate).

Methylpropanoate is an ester as RCOOR is the general formula. Esters are isomers of carboxylic acid therefore it must be carboxylic acid with 4 C atoms that is butanoic acid.

The structure is represented as follows:

Interpretation Introduction

(e)

Interpretation:

The isomer of a given compound needs to be determined.

Concept introduction:

Isomers can be defined as the organic molecules which have the same molecular formula and different structural formula.

Due to different structural formula, isomers have different physical and chemical properties.

Answer to Problem 7E

Explanation of Solution

The given structure is as follows:

The formula of the given compound is ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{NHCH}}_{\text{3}}$ (N-methylpropanamine). N-methypropanamine is a secondary amine as two alkyl groups are bonded with −NH- thus the isomer can have the same functional group with different alkyl groups as given. It will be N-ethylethanamine. The structure will be as follows:

Interpretation Introduction

(f)

Interpretation:

The isomer of given compound needs to be determined.

Concept introduction:

Isomers can be defined as the organic molecules which have the same molecular formula and different structural formula.

Due to different structural formula, isomers have different physical and chemical properties.

Answer to Problem 7E

Explanation of Solution

The given structure is as follows:

The formula of the given compound is ${\text{HCOOCH}}_{\text{3}}$. It is an ester as RCOOR is the general formula. Esters are isomers of carboxylic acid therefore it must be carboxylic acid with 2 C atoms that is ethanoic acid. The structure is as follows: