Chapter U2.9, Problem 6E

Interpretation Introduction

(a)

Interpretation:

Lewis dot structure of the given amine molecule must be drawn.

Concept introduction:

Lewis dot structure is the representation of molecule in which valence electrons are shown as dots.

Answer to Problem 6E

Lewis structure of the given amine is shown below.

Explanation of Solution

Each carbon has four valencies. The nitrogen atom has valency three. There is one lone pair on N atom. All the atoms have single bond. Each atom is octet fulfilled except hydrogen atoms which are duplet (having 2 electrons).

Interpretation Introduction

(b)

Interpretation:

Structural formula of the given amine must be drawn.

Concept introduction:

Structural formula is the representation of a molecule in which the arrangements of all the atoms are shown.

Answer to Problem 6E

Structural formula of the given amine (ethanamine) is shown below.

Explanation of Solution

Structural formula of ethanamine is drawn in which the two carbon atoms are bonded with four atoms and the nitrogen atom is bonded with two hydrogen atoms and one carbon atoms. Additionally, there is one lone pair electrons on N atom. There is no lone pair on C and H atoms.

Interpretation Introduction

(c)

Interpretation:

The functional group of the given molecule must be predicted.

Concept introduction:

Functional groups are atoms or group of atoms which controls the physical and chemical properties of the molecule.

Answer to Problem 6E

There is amine functional group in the given molecule.

Explanation of Solution

The functional group (NH₂) present in ethanamine is shown in red. It is a primary amine functional group in which the N atom is bonded with one carbon atom and two hydrogen atoms. There is also one lone pair on N atom.

Interpretation Introduction

(d)

Interpretation:

The smell and name of the given molecule must be predicted.

Concept introduction:

Organic molecule can be named easily following the IUPAC (International Union of Pure and applied Chemistry) nomenclature system. Trivial name is also there for organic molecule. Smell sometimes depends on the class of the molecule.

Answer to Problem 6E

Name of the molecule is ethanamine as per IUPAC system. Trivial name is ethyl amine. It has pungent smell like ammonia.

Explanation of Solution

Numbering of the carbon chain is done giving priority (number 1) to the functional group bearing C. Total carbon is 2. So the IUPAC name is ethanamine. As there is ethyl (C₂H₅) group attached with the amine functional group, thus it is named as ethyl amine in trivial naming system.

The smells of most of the amines are like ammonia as these are ammonia derivatives. Thus, smell of ethanamine is pungent like ammonia.