Question

Which of the following diagrams represents a general structure of a secondary amine?

A. An N bonded to two electron dots above, with a dotted triangular line to an H, a solid triangular line to an H, and a single line to an H; it is noted that the angle between the last two H atoms is 107 degrees.
B. An N with 2 electron dots linked to an R₁ group with a single line, an H with a triangular line, and an H with a dotted line.
C. An N with 2 electron dots linked to an R₁ group with a single line, an R₂ group with a triangular line, and an H with a dotted line.
D. An N with 2 electron dots linked to an R₁ group with a single line, an R₂ group with a triangular line, and an R₃ with a dotted line.

Answer 1

The structure of a secondary amine includes a nitrogen atom bonded to one hydrogen and two carbon atoms. The correct option that represents a secondary amine is Option C, where nitrogen is attached to two R groups and one hydrogen atom.

Step-by-step explanation:

To identify the general structure of a secondary amine, we need to understand the bonding of nitrogen in amines. A secondary amine has one hydrogen and two carbon atoms bonded to the nitrogen. Nitrogen has a lone pair of electrons and forms three bonds either with hydrogen or carbon atoms. Therefore, the general structure of a secondary amine includes a central nitrogen atom bonded to one hydrogen atom and two alkyl or aryl groups (denoted as R groups).

Considering the options given:

• Option A: Represents a nitrogen bonded to three hydrogen atoms; therefore, it describes ammonia or a primary amine, not a secondary amine.
• Option B: Depicts a nitrogen atom with two bonds to hydrogen, which is also representative of a primary amine.
• Option C: Shows a nitrogen atom bonded to two R groups and one hydrogen, fitting the description of a secondary amine.
• Option D: Illustrates a nitrogen attached to three R groups, which would be a tertiary amine.

The correct diagram representing a secondary amine is Option C: An N with 2 electron dots linked to an R1 group with a single line, an R2 group with a triangular line, and an H with a dotted line. This structure accurately reflects the bonding of a secondary amine where two carbon-containing R groups and one hydrogen atom are attached to nitrogen.