Questions: Draw the Lewis dot structure for NI₃.
Determine the electron geometry of NI₃.
trigonal planar
tetrahedral
linear
Transcript text: Draw the Lewis dot structure for $\mathrm{NI}_{3}$.
Determine the electron geometry of $\mathrm{NI}_{3}$.
trigonal planar
tetrahedral
linear
Solution
Solution Steps
Step 1: Determine the Total Number of Valence Electrons
To draw the Lewis dot structure for \(\mathrm{NI}_3\), we first need to determine the total number of valence electrons. Nitrogen (N) has 5 valence electrons, and each iodine (I) atom has 7 valence electrons. Therefore, the total number of valence electrons is:
\[
5 + 3 \times 7 = 26
\]
Step 2: Draw the Basic Structure
Place the nitrogen atom in the center and arrange the three iodine atoms around it. Connect each iodine atom to the nitrogen atom with a single bond. This uses up 6 electrons (3 bonds \(\times\) 2 electrons per bond).
Step 3: Distribute Remaining Electrons
Distribute the remaining 20 electrons (26 total - 6 used in bonds) to satisfy the octet rule for each iodine atom. Each iodine atom will have 6 additional electrons (3 lone pairs), using up all 18 electrons. The nitrogen atom will have one lone pair.
Step 4: Determine the Electron Geometry
The electron geometry considers both the bonding pairs and lone pairs around the central atom. Nitrogen in \(\mathrm{NI}_3\) has three bonding pairs and one lone pair, which corresponds to a tetrahedral electron geometry.
Final Answer
The electron geometry of \(\mathrm{NI}_3\) is \(\boxed{\text{tetrahedral}}\).