Draw the Lewis Structure of CH3NHNH2
The Correct Answer and Explanation is:
Lewis Structure of CH₃NHNH₂ (Methylhydrazine)
Here’s the step-by-step Lewis Structure for CH₃NHNH₂:
H H
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H - C - N - N - H
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H H
Explanation
CH₃NHNH₂, known as methylhydrazine, is an organic molecule composed of carbon (C), hydrogen (H), and nitrogen (N). To draw its Lewis structure, we must follow standard rules for Lewis structures: count valence electrons, connect atoms with bonds, and satisfy the octet rule where applicable.
1. Count Total Valence Electrons:
- C: 4 valence electrons × 1 = 4
- N: 5 valence electrons × 2 = 10
- H: 1 valence electron × 6 = 6
Total = 4 + 10 + 6 = 20 valence electrons
2. Determine Skeleton Structure:
The molecule has a methyl group (CH₃) bonded to a nitrogen (N), which is bonded to another nitrogen (N), which is then bonded to two hydrogens. So the skeletal arrangement is:
H₃C–N–N–H₂
3. Connect Atoms with Single Bonds:
- Carbon bonds to three H atoms and one N atom (CH₃–N).
- First nitrogen bonds to the methyl carbon and the second nitrogen.
- Second nitrogen bonds to the first nitrogen and two hydrogen atoms.
4. Add Lone Pairs and Complete Octets:
After connecting all atoms, distribute the remaining electrons as lone pairs, especially to nitrogen atoms which require an octet. Nitrogen typically forms 3 bonds and has one lone pair:
- The first N (connected to CH₃ and the second N) forms two bonds, so it will have one lone pair.
- The second N forms three bonds (to the first N and two H atoms), also needing one lone pair.
5. Check Octets:
- C has 4 bonds (octet complete).
- Each N has 3 bonds and 1 lone pair (octet complete).
- Each H has one bond (duet complete).
This structure is stable and satisfies formal charges and the octet rule, making it the correct Lewis structure.
