Chapter 6, Problem 31P

(a)

Interpretation Introduction

Interpretation:

The IUPAC name of ${\text{CH}}_3{\text{CH}}_2\text{Cl}$ should be determined.

Concept Introduction:

There are few steps in IUPAC nomenclature,

1. Find the longest carbon chain in the molecule and name it.
2. Number the longest carbon chain in such a way that the halogen atoms get the lowest number.
3. If there are multiple halogen atoms from same atom, a prefix as di, tri, tetra is added to denote the number of halogen atoms.
4. Different types of halogens are named in alphabetical order.
5. Position of the halogen atom is indicated by writing the number of carbon atom it is attached before the name of the parent hydrocarbon.
6. The name is ended as a normal alkane.

Answer to Problem 31P

1-chloroethane.

Explanation of Solution

  ${\text{CH}}_3{\text{CH}}_2\text{Cl}$ has only two carbons. Therefore, parent carbon chain is named as ethane. A chlorine atom is attached to C-1. So, the IUPAC name of the compound is 1-chloroethane.

(b)

Interpretation Introduction

Interpretation:

The IUPAC name of ${\text{BrCH}}_2{\text{CH}}_2\text{Br}$ should be determined.

Concept Introduction:

There are few steps in IUPAC nomenclature,

1. Find the longest carbon chain in the molecule and name it.
2. Number the longest carbon chain in such a way that the halogen atoms get the lowest number.
3. If there are multiple halogen atoms from same atom, a prefix as di, tri, tetra is added to denote the number of halogen atoms.
4. Different types of halogens are named in alphabetical order.
5. Position of the halogen atom is indicated by writing the number of carbon atom it is attached before the name of the parent hydrocarbon.
6. The name is ended as a normal alkane.

Answer to Problem 31P

1,2-dibromoethane.

Explanation of Solution

  ${\text{BrCH}}_2{\text{CH}}_2\text{Br}$ has only two carbons. Therefore, parent carbon chain is named as ethane. There are twobromine atoms attached to C-1 and C-2 positions. So, the IUPAC name of the compound is 1,2-dibromoethane.

(c)

Interpretation Introduction

Interpretation:

The IUPAC name of the following molecule should be determined.

  

Concept Introduction:

There are few steps in IUPAC nomenclature,

1. Find the longest carbon chain in the molecule and name it.
2. Number the longest carbon chain in such a way that the halogen atoms get the lowest number.
3. If there are multiple halogen atoms from same atom, a prefix as di, tri, tetra is added to denote the number of halogen atoms.
4. Different types of halogens are named in alphabetical order.
5. Position of the halogen atom is indicated by writing the number of carbon atom it is attached before the name of the parent hydrocarbon.
6. The name is ended as a normal alkane.

Answer to Problem 31P

2-ethyl-1-fluorobutane.

Explanation of Solution

  

The longest carbon chain giving the halide atom the lowest number has four carbons. So, this is a butane. There is a fluorine atom attached at C-1 and an ethyl group at C-2. Alphabetically, ethyl substituent should be written before, fluoro-. So, the IUPAC name of the compound is 2-ethyl-1-fluorobutane.

(d)

Interpretation Introduction

Interpretation:

The IUPAC name of ${{\text{(CH}}_3\text{)}}_3{\text{CCH}}_2\text{I}$ should be determined.

Concept Introduction:

There are few steps in IUPAC nomenclature,

1. Find the longest carbon chain in the molecule and name it.
2. Number the longest carbon chain in such a way that the halogen atoms get the lowest number.
3. If there are multiple halogen atoms from same atom, a prefix as di, tri, tetra is added to denote the number of halogen atoms.
4. Different types of halogens are named in alphabetical order.
5. Position of the halogen atom is indicated by writing the number of carbon atom it is attached before the name of the parent hydrocarbon.
6. The name is ended as a normal alkane.

Answer to Problem 31P

2,2-dimethyl-1-iodopropane.

Explanation of Solution

  

The longest carbon chain giving the halide atom the lowest number has three carbons. So, this is a propane. There is an iodine atom attached at C-1 and two methyl groups at C-2. Alphabetically, iodo- substituent should be written before, methyl. So, the IUPAC name of the compound is 2,2-dimethyl-1-iodopropane.

(e)

Interpretation Introduction

Interpretation:

The IUPAC name of the following molecule should be determined.

  

Concept Introduction:

There are few steps in IUPAC nomenclature,

1. Find the longest carbon chain in the molecule and name it.
2. Number the longest carbon chain in such a way that the halogen atoms get the lowest number.
3. If there are multiple halogen atoms from same atom, a prefix as di, tri, tetra is added to denote the number of halogen atoms.
4. Different types of halogens are named in alphabetical order.
5. Position of the halogen atom is indicated by writing the number of carbon atom it is attached before the name of the parent hydrocarbon.
6. The name is ended as a normal alkane.

Answer to Problem 31P

1-trichloromethylcyclohexane.

Explanation of Solution

  

This is a substituted cycloalkane. The cycloalkane has six carbons, so, it is named as cyclohexane. There is a trichloromethyl group attached to C-1 of cyclohexane. So, IUPAC name of this molecule is 1-trichloromethylcyclohexane.

(f)

Interpretation Introduction

Interpretation:

The IUPAC name of ${\text{CHBr}}_3$ should be determined.

Concept Introduction:

There are few steps in IUPAC nomenclature,

1. Find the longest carbon chain in the molecule and name it.
2. Number the longest carbon chain in such a way that the halogen atoms get the lowest number.
3. If there are multiple halogen atoms from same atom, a prefix as di, tri, tetra is added to denote the number of halogen atoms.
4. Different types of halogens are named in alphabetical order.
5. Position of the halogen atom is indicated by writing the number of carbon atom it is attached before the name of the parent hydrocarbon.
6. The name is ended as a normal alkane.

Answer to Problem 31P

Tribromomethane.

Explanation of Solution

  ${\text{CHBr}}_3$ has only one carbon. So, this is named as a methane. three bromine atoms have substituted three hydrogens. So the prefix tribromo- is added to the parent name. therefore, the IUPAC name of the molecule is tribromomethane.