Chapter 11, Problem 11A.1E

(a)

Interpretation Introduction

Interpretation:

The line structure of ${\text{CH}}_{\text{3}}{\text{CCCH}}_{\text{3}}$ and the class of hydrocarbon has to be given.

Concept Introduction:

Line structure:  Line structure is a simplest representation of a hydrocarbon.  In line structure, the chain of carbon atoms is shown as a zigzag line.  The end of each short line in the zigzag represents a carbon atom.  Since the carbon nearly always has a valence of four in organic compounds, it is not necessary to show the hydrogen atoms.

Class of hydrocarbons:

Alkanes:  Saturated hydrocarbons are called as alkanes.  Each atom in an alkane shows the presence of four single bonds in a tetrahedral arrangement with ${\text{sp}}^{\text{3}}$ hybridization.  The name of alkane ends with “-ane”.

Alkenes:  The simplest unsaturated hydrocarbon with a double bond is called as alkene.  The name of alkane ends with “-ene”.

Alkynes:  Alkynes are hydrocarbons with one carbon-carbon triple bond.  The name of the alkyne ends with “-yne”.

Answer to Problem 11A.1E

The line structure of ${\text{CH}}_{\text{3}}{\text{CCCH}}_{\text{3}}$ is,

${\text{CH}}_{\text{3}}{\text{CCCH}}_{\text{3}}$ is an alkyne.

Explanation of Solution

The given condensed formula is ${\text{CH}}_{\text{3}}{\text{CCCH}}_{\text{3}}.$  The parent chain is identified as butane.  From the formula, it is seen the compound will a carbon-carbon triple bond and the name becomes butyne.  The line formula of ${\text{CH}}_{\text{3}}{\text{CCCH}}_{\text{3}}$ is,

The presence of triple bond in the compound shows that it belongs to alkyne.

(b)

Interpretation Introduction

Interpretation:

The line structure of ${\text{CH}}_{\text{3}}{\text{CH}}_2{\text{CH}}_2{\text{CH}}_{\text{3}}$ and the class of hydrocarbon has to be given.

Concept Introduction:

Refer to part (a).

Answer to Problem 11A.1E

The line structure of ${\text{CH}}_{\text{3}}{\text{CH}}_2{\text{CH}}_2{\text{CH}}_{\text{3}}$ is,

${\text{CH}}_{\text{3}}{\text{CH}}_2{\text{CH}}_2{\text{CH}}_{\text{3}}$ is an alkane.

Explanation of Solution

The given condensed formula is ${\text{CH}}_{\text{3}}{\text{CH}}_2{\text{CH}}_2{\text{CH}}_{\text{3}}.$  The parent chain is identified as butane.  The line formula of ${\text{CH}}_{\text{3}}{\text{CH}}_2{\text{CH}}_2{\text{CH}}_{\text{3}}$ is,

The presence of single bond in the compound shows that it belongs to alkane.

(c)

Interpretation Introduction

Interpretation:

The line structure of ${\text{CH}}_{\text{2}}{\text{CHCH}}_{\text{2}}{\text{CH}}_{\text{3}}$ and the class of hydrocarbon has to be given.

Concept Introduction:

Refer to part (a).

Answer to Problem 11A.1E

The line structure of ${\text{CH}}_{\text{2}}{\text{CHCH}}_{\text{2}}{\text{CH}}_{\text{3}}$ is,

${\text{CH}}_{\text{3}}{\text{CH}}_2{\text{CH}}_2{\text{CH}}_{\text{3}}$ is an alkene.

Explanation of Solution

The given condensed formula is ${\text{CH}}_{\text{2}}{\text{CHCH}}_{\text{2}}{\text{CH}}_{\text{3}}.$  The parent chain is identified as butane.  The compound is said to have double bond in it and therefore, the name is butene.  The line formula of ${\text{CH}}_{\text{2}}{\text{CHCH}}_{\text{2}}{\text{CH}}_{\text{3}}$ is,

The presence of double bond in the compound shows that it belongs to alkene.

(d)

Interpretation Introduction

Interpretation:

The line structure of ${\text{CH}}_{\text{3}}{\text{CHCHCH}}_2{\text{CCCH}}_{\text{3}}$ and the class of hydrocarbon has to be given.

Concept Introduction:

Refer to part (a).

Answer to Problem 11A.1E

The line structure of ${\text{CH}}_{\text{3}}{\text{CHCHCH}}_2{\text{CCCH}}_{\text{3}}$ is,

In ${\text{CH}}_{\text{3}}{\text{CHCHCH}}_2{\text{CCCH}}_{\text{3}},$ the ${\text{CH}}_{\text{3}}{\text{CHCHCH}}_{\text{2}}$ part is an alkene and ${\text{CH}}_{\text{2}}{\text{CCCH}}_{\text{3}}$ is an alkyne.

Explanation of Solution

The given condensed formula is ${\text{CH}}_{\text{3}}{\text{CHCHCH}}_2{\text{CCCH}}_{\text{3}}.$  The parent chain is heptane and one double bond is present in second carbon atom and one triple bond is present in carbon five position.  The name of hydrocarbon becomes $\text{hept-2-en-5yne}\text{.}$  The line structure is,

In ${\text{CH}}_{\text{3}}{\text{CHCHCH}}_2{\text{CCCH}}_{\text{3}},$ the ${\text{CH}}_{\text{3}}{\text{CH=CHCH}}_{\text{2}}$ part shows the presence of double bond, is alkene and ${\text{CH}}_{\text{2}}\text{C}\equiv {\text{CCH}}_{\text{3}}$ is an alkyne as it shows the presence of triple bond.

(e)

Interpretation Introduction

Interpretation:

The line structure of ${\text{CH}}_{\text{2}}\text{CHCH}{\text{2}}_{}{\text{CHCH}}_{\text{2}}$ and the class of hydrocarbon has to be given.

Concept Introduction:

Refer to part (a).

Answer to Problem 11A.1E

The line structure of ${\text{CH}}_{\text{2}}\text{CHCH}{\text{2}}_{}{\text{CHCH}}_{\text{2}}$ is,

${\text{CH}}_{\text{2}}\text{CHCH}{\text{2}}_{}{\text{CHCH}}_{\text{2}}$ is an alkene.

Explanation of Solution

The given condensed formula is ${\text{CH}}_{\text{2}}\text{CHCH}{\text{2}}_{}{\text{CHCH}}_{\text{2}}.$  The parent chain is identified as pentane.  From the formula, it can be seen that the compound consists of two double bonds in the first and fourth position of carbon atoms respectively.  The line formula of ${\text{CH}}_{\text{2}}\text{CHCH}{\text{2}}_{}{\text{CHCH}}_{\text{2}}$ is,

The presence of double bonds in the compound shows that it belongs to alkene.