The nitrite ion NO2 has total valence electrons.

The nitrite ion NO2 has total valence electrons. Draw the Lewis structure, including nonbonding pairs, for dibromomethane CH2Br2. There are valence electrons. Using methane (see Procedure) as an example, draw CH2Br2 so that its shape includes nonbonding pairs where relevant. For CH2Br2, the domain geometry is. The molecular geometry is. This molecule is polar or nonpolar.

The Correct Answer and Explanation is:

Let’s break this into parts for clarity:

Lewis Structure for CH2Br2:

1. Valence Electrons in CH2Br2:
   • Carbon (C) has 4 valence electrons.
   • Hydrogen (H) has 1 valence electron each, and there are 2 hydrogens: 2 × 1 = 2 valence electrons.
   • Bromine (Br) has 7 valence electrons each, and there are 2 bromines: 2 × 7 = 14 valence electrons.
   So, the total number of valence electrons is: 4 (from C)+2 (from H’s)+14 (from Br’s)=20 valence electrons.4 \, (\text{from C}) + 2 \, (\text{from H’s}) + 14 \, (\text{from Br’s}) = 20 \, \text{valence electrons}.4(from C)+2(from H’s)+14(from Br’s)=20valence electrons.
2. Drawing the Lewis Structure:
   • Carbon will be the central atom, as it can form 4 bonds.
   • Each hydrogen atom will be bonded to carbon with a single bond.
   • Each bromine will also form a single bond with carbon.
   In the Lewis structure, you can place the 20 valence electrons around the atoms, making sure that each atom (except hydrogen) follows the octet rule. The structure will look like this: H−C−Br\text{H} – \text{C} – \text{Br}H−C−Br H−C−Br\text{H} – \text{C} – \text{Br}H−C−Br Carbon has 4 bonds (with 2 hydrogens and 2 bromines), so no lone pairs on carbon. Bromine atoms each have 3 lone pairs of electrons (6 electrons), and hydrogen atoms have no lone pairs.

Geometry and Shape:

• Domain Geometry:
  CH2Br2 has four regions of electron density (2 bonds with hydrogens and 2 with bromines), so the domain geometry is tetrahedral.
• Molecular Geometry:
  Since there are no lone pairs on the central carbon, the molecular geometry is also tetrahedral.

Polarity of CH2Br2:

• Polarity:
  The molecule is polar because bromine atoms are more electronegative than hydrogen atoms, creating a dipole moment. The asymmetry in the distribution of charge (with two bromine atoms and two hydrogen atoms) causes the dipole moments to not cancel out, making the molecule overall polar.

Conclusion:

• Valence Electrons: 20
• Domain Geometry: Tetrahedral
• Molecular Geometry: Tetrahedral
• Polarity: Polar