Question

draw the lewis structure for ethylamine (c₂h₇n). ethylamine molecules have one amino group. be certain you include any lone pairs.

Explanation:

1. Determine the molecular formula and connectivity: Ethylamine has the formula \( C_2H_7N \). The structure is based on an ethyl group (\( -CH_2CH_3 \)) attached to an amino group (\( -NH_2 \)), so the connectivity is \( CH_3 - CH_2 - NH_2 \).
2. Count valence electrons:

• Carbon (\( C \)) has 4 valence electrons, and there are 2 \( C \) atoms: \( 2\times4 = 8 \).
• Hydrogen (\( H \)) has 1 valence electron, and there are 7 \( H \) atoms: \( 7\times1 = 7 \).
• Nitrogen (\( N \)) has 5 valence electrons: \( 5 \).
• Total valence electrons: \( 8 + 7 + 5 = 20 \).

1. Draw single bonds first:

• Connect the atoms with single bonds. The \( C - C \) bond, \( C - N \) bond, and all \( C - H \) and \( N - H \) bonds are single bonds.
• The \( C - C \) bond uses 2 electrons, the \( C - N \) bond uses 2 electrons, the five \( C - H \) bonds (since one \( C \) has 3 \( H \) and the other has 2 \( H \)) use \( 5\times2 = 10 \) electrons, and the two \( N - H \) bonds use \( 2\times2 = 4 \) electrons.
• Total electrons used in single bonds: \( 2 + 2 + 10 + 4 = 18 \).

1. Assign remaining electrons as lone pairs:

• Remaining electrons: \( 20 - 18 = 2 \). These go on the nitrogen atom as a lone pair (since nitrogen needs an octet, and it currently has 6 electrons from the three bonds ( \( C - N \) and two \( N - H \) bonds), so adding a lone pair (2 electrons) gives it 8 electrons (an octet)).

1. Final structure:

• The Lewis structure is \( \text{H}_3\text{C} - \text{CH}_2 - \text{NH}_2 \), with the nitrogen atom having one lone pair (two dots) to complete its octet. The carbon atoms have four bonds (satisfying the octet rule), and hydrogen atoms have two electrons (satisfying the duet rule).

Answer:

The Lewis structure of ethylamine (\( C_2H_7N \)) is \( \boldsymbol{\text{H}_3\text{C} - \text{CH}_2 - \text{NH}_2} \) with a lone pair (two non - bonding electrons) on the nitrogen atom. The structural representation (using the drawing tools) would show:

• Two carbon atoms connected by a single bond.
• One carbon atom bonded to three hydrogen atoms, and the other carbon atom bonded to two hydrogen atoms and one nitrogen atom.
• The nitrogen atom bonded to two hydrogen atoms and has one lone pair of electrons.