The Lewis structure for N2H4, also known as hydrazine, can be drawn by following these steps:
- Count the total number of valence electrons: Nitrogen (N) has 5 valence electrons, and hydrogen (H) has 1. Since there are two nitrogen atoms and four hydrogen atoms, the total number of valence electrons is (2 × 5) + (4 × 1) = 14.
- Determine the central atom: In N2H4, the two nitrogen atoms are the central atoms, and the hydrogen atoms are bonded to them.
- Draw the skeletal structure: Place the two nitrogen atoms in the center with a single bond between them. Then, attach two hydrogen atoms to each nitrogen atom.
- Distribute the remaining electrons: After forming the single bonds, you will have 10 electrons left. These electrons are used to complete the octets of the nitrogen atoms. Each nitrogen atom will have a lone pair of electrons.
- Check the octet rule: Ensure that each nitrogen atom has 8 electrons around it (including the lone pairs and the bonding electrons).
The final Lewis structure for N2H4 looks like this:
H H \ / N-N / \ H H
In this structure, the two nitrogen atoms are connected by a single bond, and each nitrogen atom is bonded to two hydrogen atoms. Each nitrogen atom also has a lone pair of electrons.