After drawing the Lewis structure of H2CS (thioformaldehyde), what are the electron domain geometry and molecular geometry around the central carbon atom?

• A. Electron domain geometry: trigonal planar; Molecular geometry: trigonal planar
• B. Electron domain geometry: tetrahedral; Molecular geometry: tetrahedral
• C. Electron domain geometry: trigonal planar; Molecular geometry: bent
• D. Electron domain geometry: linear; Molecular geometry: linear

Answer: (A)

Verified step by step guidance

1. Step 1: Draw the Lewis structure of H2CS. Place carbon (C) as the central atom, connect it to two hydrogen (H) atoms and one sulfur (S) atom. Count the total valence electrons: C has 4, each H has 1, and S has 6, for a total of 4 + 2(1) + 6 = 12 electrons.
2. Step 2: Arrange the electrons to satisfy the octet rule for carbon and sulfur. Carbon forms two single bonds with hydrogen atoms and a double bond with sulfur to complete its octet. This results in three regions of electron density (two C-H single bonds and one C=S double bond) around the carbon atom.
3. Step 3: Determine the electron domain geometry by considering all regions of electron density (bonding and lone pairs) around the central atom. Since there are three regions of electron density and no lone pairs on carbon, the electron domain geometry is trigonal planar.
4. Step 4: Determine the molecular geometry by considering only the positions of atoms (ignoring lone pairs on the central atom). Because there are no lone pairs on carbon and three bonded atoms, the molecular geometry is also trigonal planar.
5. Step 5: Conclude that both the electron domain geometry and molecular geometry around the central carbon atom in H2CS are trigonal planar.