Chapter 18.1, Problem 18.3P

Interpretation Introduction

(a)

Interpretation:

The amine in the methamphetamine is to be labeled as 1°(primary), 2° (secondary) or 3°(tertiary)-

Concept Introduction:

Amines are organic compounds which are derived from ammonia by replacing one or more hydrogen atoms of ammonia by the alkyl groups. The amines can be classified as

1. Primary amines ( ${\text{RNH}}_2$ ) - When one hydrogen of ammonia is replaced by the alkyl or aryl group.
2. Secondary amines ( ${\text{R}}_2\text{NH}$ ) - When two hydrogen atoms of ammonia are replaced by the alkyl or aryl groups.
3. Tertiary amine ( ${\text{R}}_3\text{N}$ ) - When all three hydrogen atoms of ammonia are replaced by the alkyl or aryl groups.

Interpretation Introduction

(b)

Interpretation:

The molecular shape around each indicated atom in the methamphetamine is to be given.

Concept Introduction:

• Molecular shape is defined as the 3-D arrangement of atoms in a molecule.
• The molecular shape of sp² hybridized atom is trigonal planar.
• According to VSEPR-

Number of atoms bonded to the central atom	Number of lone pairs	Molecular shape
2	0	Linear
2	1	Bent
3	0	Trigonal planar
3	1	Trigonal pyramidal
4	0	Tetrahedral