Chapter 20, Problem 8A

(a)

Interpretation Introduction

Interpretation:The structural formula of the straight-chain alkanes of pentane is to be drawn.

Concept Introduction: Alkanes are the hydrocarbons which contain Carbon carbon single bond and are called saturated hydrocarbons.

Answer to Problem 8A

  $\begin{array}{l}\\ \text{H}\text{H}\text{H}\text{H}\text{H}\\ \left|\right|\left|\right||\\ \text{H}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{H}\\ \left|\right|\left|\right||\\ \text{H}\text{H}\text{H}\text{H}\text{H}\\ \end{array}$

Explanation of Solution

The alkane with five carbon atoms can be written as $\begin{array}{l}\\ \text{H}\text{H}\text{H}\text{H}\text{H}\\ \left|\right|\left|\right||\\ \text{H}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{H}\\ \left|\right|\left|\right||\\ \text{H}\text{H}\text{H}\text{H}\text{H}\\ \end{array}$ which can be condensed to ${\text{CH}}_{\text{3}}-{({\text{CH}}_{\text{2}})}_3-{\text{CH}}_{\text{3}}$ .

(b)

Interpretation Introduction

Interpretation:The structural formula of the straight-chain alkanes of undecane is to be drawn.

Concept Introduction: Alkanes are the hydrocarbons which contain Carbon carbon single bond and are called saturated hydrocarbons.

Answer to Problem 8A

  $\begin{array}{l}\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \left|\right|\left|\right|\left|\right|\left|\right|\left|\right||\\ \text{H}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{H}\\ \left|\right|\left|\right|\left|\right|\left|\right|\left|\right||\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \end{array}$

Explanation of Solution

The alkane with eleven carbon atoms can be written as $\begin{array}{l}\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \left|\right|\left|\right|\left|\right|\left|\right|\left|\right||\\ \text{H}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{H}\\ \left|\right|\left|\right|\left|\right|\left|\right|\left|\right||\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \end{array}$

which can be condensed to ${\text{CH}}_3-{\left({\text{CH}}_2\right)}_9-{\text{CH}}_{\text{3}}$ .

(c)

Interpretation Introduction

Interpretation:The structural formula of the straight-chain alkanes of nonane is to be drawn.

Concept Introduction: Alkanes are the hydrocarbons which contain Carbon carbon single bond and are called saturated hydrocarbons.

Answer to Problem 8A

  $\begin{array}{l}\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \left|\right|\left|\right|\left|\right|\left|\right||\\ \text{H}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{H}\\ \left|\right|\left|\right|\left|\right|\left|\right||\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \end{array}$

Explanation of Solution

The alkane with nine carbon atoms can be written as $\begin{array}{l}\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \left|\right|\left|\right|\left|\right|\left|\right||\\ \text{H}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{H}\\ \left|\right|\left|\right|\left|\right|\left|\right||\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \end{array}$

which can be condensed to ${\text{CH}}_3-{\left({\text{CH}}_2\right)}_7-{\text{CH}}_{\text{3}}$ .

(d)

Interpretation Introduction

Interpretation:The structural formula of the straight-chain alkanes of heptane is to be drawn.

Concept Introduction: Alkanes in which the carbon atoms form long “strings” or chains are called normal, straight-chain, or unbranched hydrocarbons.

Answer to Problem 8A

  $\begin{array}{l}\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \left|\right|\left|\right|\left|\right||\\ \text{H}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{H}\\ \left|\right|\left|\right|\left|\right||\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \end{array}$

Explanation of Solution

The alkane with seven carbon atoms can be written as $\begin{array}{l}\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \left|\right|\left|\right|\left|\right||\\ \text{H}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{C}-\text{H}\\ \left|\right|\left|\right|\left|\right||\\ \text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\text{H}\\ \end{array}$ which can be condensed to ${\text{CH}}_{\text{3}}-{({\text{CH}}_{\text{2}})}_5-{\text{CH}}_{\text{3}}$ .