Chapter 12, Problem 12.21EP

(a)

Interpretation Introduction

Interpretation:

The expanded structural formula of a continuous-chain alkane with the formula ${\text{C}}_{\text{5}}{\text{H}}_{\text{12}}$ has to be drawn.

Concept Introduction:

The structural representation of organic compound can be done in 2D and 3D.  In two-dimensional representation, there are four types of representation in which an organic compound can be drawn.  They are,

• Expanded structural formula
• Condensed structural formula
• Skeletal structural formula
• Line-angle structural formula

Structural formula which shows all the atoms in a molecule along with all the bonds that is connecting the atoms present in the molecule is known as Expanded structural formula.

Structural formula in which grouping of atoms are done and in which the central atoms along with the other atoms are connected to them are treated as group is known as Condensed structural formula.

Structural formula that shows the bonding between carbon atoms alone in the molecule ignoring the hydrogen atoms being shown explicitly is known as Skeletal structural formula.

Structural formula where a line represent carbon‑carbon bond and the carbon atom is considered to be present in each point and the end of lines is known as Line-angle structural formula.

In condensed structural formula for alkanes, the repeating ${\text{CH}}_{\text{2}}$ group can be represented using parentheses and subscript.  Subscript here represents the number of times the ${\text{CH}}_{\text{2}}$ group is repeated in a continuous chain.

(b)

Interpretation Introduction

Interpretation:

The expanded structural formula for ${\text{CH}}_{\text{3}}-{{\text{(CH}}_{\text{2}}\text{)}}_{\text{6}}-{\text{CH}}_{\text{3}}$ has to be drawn.

Concept Introduction:

The structural representation of organic compound can be done in 2D and 3D.  In two-dimensional representation, there are four types of representation in which an organic compound can be drawn.  They are,

• Expanded structural formula
• Condensed structural formula
• Skeletal structural formula
• Line-angle structural formula

Structural formula which shows all the atoms in a molecule along with all the bonds that is connecting the atoms present in the molecule is known as Expanded structural formula.

Structural formula in which grouping of atoms are done and in which the central atoms along with the other atoms are connected to them are treated as group is known as Condensed structural formula.

Structural formula that shows the bonding between carbon atoms alone in the molecule ignoring the hydrogen atoms being shown explicitly is known as Skeletal structural formula.

Structural formula where a line represent carbon‑carbon bond and the carbon atom is considered to be present in each point and the end of lines is known as Line-angle structural formula.

In condensed structural formula for alkanes, the repeating ${\text{CH}}_{\text{2}}$ group can be represented using parentheses and subscript.  Subscript here represents the number of times the ${\text{CH}}_{\text{2}}$ group is repeated in a continuous chain.

(c)

Interpretation Introduction

Interpretation:

The condensed structural formula of a continuous-chain alkane with the formula ${\text{C}}_{\text{10}}{\text{H}}_{\text{22}}$ has to be drawn with parentheses and subscript.

Concept Introduction:

The structural representation of organic compound can be done in 2D and 3D.  In two-dimensional representation, there are four types of representation in which an organic compound can be drawn.  They are,

• Expanded structural formula
• Condensed structural formula
• Skeletal structural formula
• Line-angle structural formula

Structural formula which shows all the atoms in a molecule along with all the bonds that is connecting the atoms present in the molecule is known as Expanded structural formula.

Structural formula in which grouping of atoms are done and in which the central atoms along with the other atoms are connected to them are treated as group is known as Condensed structural formula.

Structural formula that shows the bonding between carbon atoms alone in the molecule ignoring the hydrogen atoms being shown explicitly is known as Skeletal structural formula.

Structural formula where a line represent carbon‑carbon bond and the carbon atom is considered to be present in each point and the end of lines is known as Line-angle structural formula.

In condensed structural formula for alkanes, the repeating ${\text{CH}}_{\text{2}}$ group can be represented using parentheses and subscript.  Subscript here represents the number of times the ${\text{CH}}_{\text{2}}$ group is repeated in a continuous chain.

(d)

Interpretation Introduction

Interpretation:

The molecular formula for the given alkane has to be given.

Concept Introduction:

The structural representation of organic compound can be done in 2D and 3D.  In two-dimensional representation, there are four types of representation in which an organic compound can be drawn.  They are,

• Expanded structural formula
• Condensed structural formula
• Skeletal structural formula
• Line-angle structural formula

Structural formula which shows all the atoms in a molecule along with all the bonds that is connecting the atoms present in the molecule is known as Expanded structural formula.

Structural formula in which grouping of atoms are done and in which the central atoms along with the other atoms are connected to them are treated as group is known as Condensed structural formula.

Structural formula that shows the bonding between carbon atoms alone in the molecule ignoring the hydrogen atoms being shown explicitly is known as Skeletal structural formula.

Structural formula where a line represent carbon‑carbon bond and the carbon atom is considered to be present in each point and the end of lines is known as Line-angle structural formula.

In condensed structural formula for alkanes, the repeating ${\text{CH}}_{\text{2}}$ group can be represented using parentheses and subscript.  Subscript here represents the number of times the ${\text{CH}}_{\text{2}}$ group is repeated in a continuous chain.

Molecular formula of alkane can be found from condensed structural formula, by simply counting the number of carbon atoms and hydrogen atoms present in the structural formula.