Chapter 15, Problem 15.21P

(a)

Interpretation Introduction

Interpretation:

The structure of 4-methylhexane has to be drawn and correct name has to be given.

Concept Introduction:

The hydrocarbons which contains only single bonds are said to be Alkanes.  The general formula for alkanes can be given as ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  All carbon atoms are ${\text{sp}}^{\text{3}}$ hybridized.

The Alkanes are named following some rules:

• The name of the alkane is given by the number of carbon atoms present in the chain.  It is said to be Root of the alkane.

Root = number of carbon atoms in chain.

• To name the root, for one carbon atom, the root name use is meth-.  For two carbon atoms, the root name is eth-, for three carbon atoms, it is prop-, for four carbon atoms, it is but-, for five carbon atoms, it is pent- and so on.
• The carbon chain is numbered in a way that the substituents get lowest number possible.
• The root name is followed by Suffix.  Suffix indicates the functional group present in the compound.  It is placed after the root name.

Suffix = name of the functional group present in the compound.

• The root name also contains Prefix.  Prefix is the groups attached to the root.  It indicates the branched carbon atoms on the root chain and name according to the root specifying the carbon number on which it is placed.  It contains –yl in name end.  The prefix is placed before the root name.

Prefix = name of the branched carbon atoms on chain.

• The name of the alkane is given in the form

Prefix + Root + Suffix

(b)

Interpretation Introduction

Interpretation:

The structure of 2-ethylpentane has to be drawn and correct name has to be given.

Concept Introduction:

The hydrocarbons which contains only single bonds are said to be Alkanes.  The general formula for alkanes can be given as ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  All carbon atoms are ${\text{sp}}^{\text{3}}$ hybridized.

The Alkanes are named following some rules:

• The name of the alkane is given by the number of carbon atoms present in the chain.  It is said to be Root of the alkane.

Root = number of carbon atoms in chain.

• To name the root, for one carbon atom, the root name use is meth-.  For two carbon atoms, the root name is eth-, for three carbon atoms, it is prop-, for four carbon atoms, it is but-, for five carbon atoms, it is pent- and so on.
• The carbon chain is numbered in a way that the substituents get lowest number possible.
• The root name is followed by Suffix.  Suffix indicates the functional group present in the compound.  It is placed after the root name.

Suffix = name of the functional group present in the compound.

• The root name also contains Prefix.  Prefix is the groups attached to the root.  It indicates the branched carbon atoms on the root chain and name according to the root specifying the carbon number on which it is placed.  It contains –yl in name end.  The prefix is placed before the root name.

Prefix = name of the branched carbon atoms on chain.

• The name of the alkane is given in the form

Prefix + Root + Suffix

(c)

Interpretation Introduction

Interpretation:

The structure of 2-methylcyclohexane has to be drawn and correct name has to be given.

Concept Introduction:

The hydrocarbons which contains only single bonds are said to be Alkanes.  The general formula for cycloalkanes can be given as ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.

The cycloalkanes are named following some rules:

• The name of the cycloalkane is given by the number of carbon atoms present in the ring.  It is said to be Root of the cycloalkane.

Root = number of carbon atoms in ring.

• To name the root, for one carbon atom, the root name use is meth-.  For two carbon atoms, the root name is eth-, for three carbon atoms, it is prop-, for four carbon atoms, it is but-, for five carbon atoms, it is pent- and so on.
• The carbon ring is numbered in a way that the carbon with substituents get the first number in the ring.
• The root name is followed by Suffix.  Suffix indicates the functional group present in the compound.  It is placed after the root name.

Suffix = name of the functional group present in the compound.

• The root name also contains Prefix.  Prefix is the groups attached to the root.  It indicates the branched carbon atoms on the root chain and name according to the root specifying the carbon number on which it is placed.  It contains –yl in name end.  The prefix is placed before the root name.

Prefix = name of the branched carbon atoms on chain.

• The name of the alkane is given in the form

Prefix + Root + Suffix

(d)

Interpretation Introduction

Interpretation:

The structure of 3,3-methyl-4-ethyloctane has to be drawn and correct name has to be given.

Concept Introduction:

The hydrocarbons which contains only single bonds are said to be Alkanes.  The general formula for alkanes can be given as ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  All carbon atoms are ${\text{sp}}^{\text{3}}$ hybridized.

The Alkanes are named following some rules:

• The name of the alkane is given by the number of carbon atoms present in the chain.  It is said to be Root of the alkane.

Root = number of carbon atoms in chain.

• To name the root, for one carbon atom, the root name use is meth-.  For two carbon atoms, the root name is eth-, for three carbon atoms, it is prop-, for four carbon atoms, it is but-, for five carbon atoms, it is pent- and so on.
• The carbon chain is numbered in a way that the substituents get lowest number possible.
• The root name is followed by Suffix.  Suffix indicates the functional group present in the compound.  It is placed after the root name.

Suffix = name of the functional group present in the compound.

• The root name also contains Prefix.  Prefix is the groups attached to the root.  It indicates the branched carbon atoms on the root chain and name according to the root specifying the carbon number on which it is placed.  It contains –yl in name end.  The prefix is placed before the root name.

Prefix = name of the branched carbon atoms on chain.

• The name of the alkane is given in the form

Prefix + Root + Suffix