Which of the following correctly describes the dipole moment of an H2S molecule?

• A. H2S has no net dipole moment because the molecule is linear.
• B. H2S has a net dipole moment pointing from the hydrogen atoms toward the sulfur atom.
• C. H2S has zero dipole moment because the electronegativities of hydrogen and sulfur are equal.
• D. H2S has a net dipole moment pointing from the sulfur atom toward the hydrogen atoms.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the molecular geometry of H2S. H2S has a bent (angular) shape similar to water (H2O) because sulfur has two lone pairs of electrons, which affect the shape according to VSEPR theory.
2. Step 2: Recall that dipole moments arise from differences in electronegativity between bonded atoms and the geometry of the molecule. The dipole moment points from the less electronegative atom to the more electronegative atom.
3. Step 3: Compare the electronegativities of hydrogen and sulfur. Sulfur is more electronegative than hydrogen, so the bond dipoles point from hydrogen toward sulfur.
4. Step 4: Because the molecule is bent, the individual bond dipoles do not cancel out. Instead, they add vectorially to give a net dipole moment pointing toward the sulfur atom.
5. Step 5: Conclude that H2S has a net dipole moment pointing from the hydrogen atoms toward the sulfur atom, consistent with the bent shape and electronegativity differences.