Answer
See the explanation
Work Step by Step
To draw the Lewis structure for the N,N-dimethylformamide molecule, we need to follow these steps:
1. Determine the total number of valence electrons:
- Nitrogen (N) has 5 valence electrons
- Oxygen (O) has 6 valence electrons
- Carbon (C) has 4 valence electrons
- Hydrogen (H) has 1 valence electron each
- Total valence electrons = 5 + 6 + 4 + (3 × 1) = 16
2. Arrange the atoms in the skeletal structure:
- The skeletal structure is given as: $\underset {\uparrow }{C}H-CH_{3}$
3. Draw the Lewis structure:
- Place the carbon atom at the center, with the oxygen atom and the two methyl groups (CH3) attached.
- Distribute the remaining valence electrons to form single bonds and fill the octet of each atom.
- The resulting Lewis structure is:
${H3C-C(=O)-N(CH3)2}$
4. Resonance structures:
The presence of a partial double bond character in the C-N bond can be supported by the following resonance structures:
Resonance Structure 1:
${H3C-C(=O)-N(CH3)2}$
Resonance Structure 2:
${H3C-C(=O)^{-}-N^{+}(CH3)2}$
The resonance structures show the delocalization of electrons between the carbon, oxygen, and nitrogen atoms, which contributes to the partial double bond character of the C-N bond.
