. Draw the Lewis structure of NCI
. a. Calculate the formal charges of each atom. b. Predict the molecular geometry. c. What is the hybridization state of N? d. Does NCl
has dipole moment?
The Correct Answer and Explanation is:
Lewis Structure and Molecular Properties of NCl (Nitrogen Monochloride)
1. Lewis Structure of NCl:
Nitrogen (N) has 5 valence electrons, and chlorine (Cl) has 7 valence electrons. Together, NCl has 12 valence electrons.
- Place N in the center and form a single bond with Cl.
- Use 2 electrons for the N–Cl bond.
- Distribute the remaining 10 electrons as lone pairs. Place 6 electrons (3 lone pairs) on Cl and 4 electrons (2 lone pairs) on N.
The Lewis structure:
markdownCopyEdit :N:—Cl:
..
Each atom gets an octet, and the total number of electrons used is 12.
a. Formal Charges:
Formal charge = (Valence electrons) – (Lone pair electrons) – (Bonding electrons ÷ 2)
- Nitrogen: 5 – 4 – (2 ÷ 2) = 5 – 4 – 1 = 0
- Chlorine: 7 – 6 – (2 ÷ 2) = 7 – 6 – 1 = 0
Both atoms have a formal charge of 0, so the structure is stable.
b. Molecular Geometry:
There are two bonding regions (one bonding pair and two lone pairs) around nitrogen, so the electron-pair geometry is tetrahedral, but because there is only one bonded atom, the molecular geometry is linear.
However, this is a diatomic molecule, so by default, its molecular shape is linear.
c. Hybridization State of N:
Nitrogen has one sigma bond and two lone pairs, indicating three regions of electron density. This corresponds to sp² hybridization.
d. Does NCl Have a Dipole Moment?
Yes, NCl has a dipole moment. Nitrogen and chlorine have different electronegativities, and the molecule is asymmetric due to this difference. The electron density is pulled more toward chlorine, making the molecule polar.
Summary
- Lewis structure: N single bonded to Cl, each with lone pairs
- Formal charges: Both atoms have 0
- Molecular geometry: Linear (diatomic)
- Hybridization of N: sp²
- Dipole moment: Yes, NCl is polar due to the electronegativity difference between N and Cl
