raw the Lewis structure For ethylamine (CH3CH2NH2). (Assign lone pairs where appropriate.) l Marvin as @ Help I Edit drawing £3 (b) Determine the number of nonbonding valence electrons present in a molecule of ethylamine (CH3CH2NH2). There are _ nonbonding valence electron(s) within a molecule of ethylamine. They all belong to the nitrogen atom.
The Correct Answer and Explanation is:
Correct Answer:
There are 2 nonbonding valence electrons in a molecule of ethylamine (CH₃CH₂NH₂), and they are located on the nitrogen atom.
Explanation (300+ words):
Ethylamine (CH₃CH₂NH₂) is an organic compound containing carbon (C), hydrogen (H), and nitrogen (N). To determine the number of nonbonding valence electrons, we first examine the Lewis structure and then focus on the electron configuration of nitrogen, the atom responsible for the lone pair.
Step 1: Draw the Lewis Structure of Ethylamine
Ethylamine consists of an ethyl group (CH₃CH₂–) bonded to an amino group (–NH₂). Here’s the step-by-step breakdown:
- The first carbon (C1) is bonded to three hydrogen atoms and to the second carbon (C2).
- The second carbon (C2) is bonded to two hydrogen atoms and to a nitrogen atom.
- The nitrogen atom is bonded to two hydrogen atoms and to the second carbon (C2).
So, the bonding structure looks like this:
H H H H H
| | | | |
H—C—C—N—H
|
HEach dash represents a shared pair of bonding electrons (a single covalent bond).
Step 2: Valence Electrons and Bonding
- Carbon has 4 valence electrons and forms 4 bonds (no lone pairs).
- Hydrogen has 1 valence electron and forms 1 bond (no lone pairs).
- Nitrogen has 5 valence electrons. In ethylamine, nitrogen forms three sigma bonds: one with carbon and two with hydrogen. This uses 3 electrons, forming 3 bonding pairs.
- The remaining 2 valence electrons (1 pair) on nitrogen are nonbonding, also known as a lone pair.
Step 3: Nonbonding Electrons in the Molecule
Only the nitrogen atom carries a lone pair in ethylamine. The carbon and hydrogen atoms do not have nonbonding electrons, as all of their valence electrons are involved in bonding.
Conclusion
Therefore, ethylamine (CH₃CH₂NH₂) has only one lone pair of electrons, consisting of 2 nonbonding valence electrons, and they reside entirely on the nitrogen atom. These nonbonding electrons are crucial for ethylamine’s ability to act as a Lewis base in chemical reactions, especially in forming hydrogen bonds and donating electrons in nucleophilic attacks.