A. Lewis Structures Review Lewis Structure Review Draw the Lewis structure of the following molecules and match the molecule with its structural characteristics: Drag and drop options on the right-hand side and submit. For keyboard navigation… SHOW MORE CH4 HS2 NH3 3 bonding electron pairs; 2 lone electron pairs 1 bonding electron pairs; 3 lone electron pairs 2 bonding electron pairs; 0 lone electron pairs 2 bonding electron pairs; 2 lone electron pairs 3 bonding electron pairs; 1 lone electron pairs 4 bonding electron pairs; 0 lone electron pairs
The Correct Answer and Explanation is:
Let’s review the Lewis structures and determine their structural characteristics:
1. CH4 (Methane)
- Lewis Structure: Carbon (C) is the central atom and forms four single bonds with hydrogen (H) atoms. Each hydrogen atom shares one electron with carbon, and carbon shares one electron with each hydrogen atom. There are no lone pairs on the central atom (carbon).
- Structural Characteristic: 4 bonding electron pairs; 0 lone electron pairs.
- Explanation: Since carbon shares electrons with four hydrogen atoms, all four electron pairs are bonding pairs. The molecule adopts a tetrahedral geometry, which minimizes electron pair repulsion.
2. HS2 (Hydrosulfuric acid, H2S)
- Lewis Structure: Sulfur (S) is the central atom, bonded to two hydrogen (H) atoms. Sulfur also has two lone pairs of electrons.
- Structural Characteristic: 2 bonding electron pairs; 2 lone electron pairs.
- Explanation: In this structure, sulfur forms two bonds with hydrogen atoms, and the remaining four electrons on sulfur are lone pairs. The molecule adopts a bent geometry due to lone pair repulsion, with the bond angle less than 180°.
3. NH3 (Ammonia)
- Lewis Structure: Nitrogen (N) is the central atom, bonded to three hydrogen (H) atoms. Nitrogen has one lone pair of electrons.
- Structural Characteristic: 3 bonding electron pairs; 1 lone electron pair.
- Explanation: Nitrogen shares electrons with three hydrogen atoms, leaving one lone pair of electrons on nitrogen. The geometry is trigonal pyramidal, with the lone pair causing the bond angle to be less than the ideal 109.5°.
Matching Molecules to Structural Characteristics:
- CH4: 4 bonding electron pairs; 0 lone electron pairs.
- HS2: 2 bonding electron pairs; 2 lone electron pairs.
- NH3: 3 bonding electron pairs; 1 lone electron pair.
These are the correct matchings based on the Lewis structure of each molecule. The bonding and lone pairs determine the molecular geometry and overall shape.
