Draw the Lewis structure for COCl?, including lone pairs. Select Draw Rings More Erase C O Cl :O: :: :Cl—C—Cl: What is the molecular shape of COCl?? ? bent ? linear ? trigonal pyramidal ? tetrahedral ? trigonal planar What is the Cl-C-Cl bond angle? ? 180° ? 109.5° ? 120° ? <109.5° The C-Cl bond in COCl? is The Lewis structures of four compounds are given. ::O=S=O:: ::O=C=O:: H H :Cl: :Cl: C C :Cl: :Cl: H H :Cl: Which of these molecules are polar? ? CH?Cl? ? PCl? ? SO? ? CO? The molecule COCl? is
The Correct Answer and Explanation is:
Correct Answers:
- Lewis Structure for COCl₂ (Phosgene):
The Lewis structure is: mathematicaCopyEdit:O: || Cl–C–Cl .. ..- Carbon (C) is the central atom, forming two single bonds with chlorine (Cl) atoms and a double bond with the oxygen (O) atom.
- The oxygen atom has two lone pairs.
- Each chlorine atom has three lone pairs.
- Carbon has no lone pairs (8 electrons total, fulfilling the octet rule).
- Molecular Shape:
→ Trigonal planar - Cl–C–Cl Bond Angle:
→ 120° - The C–Cl bond in COCl₂ is:
→ Polar - Which of the following molecules are polar?
- CH₂Cl₂ ✅ (Polar — asymmetrical dipole moments)
- PCl₃ ✅ (Polar — lone pair on P causes a trigonal pyramidal shape)
- SO₂ ✅ (Polar — bent shape)
- CO₂ ❌ (Non-polar — linear with equal and opposite dipoles)
- The molecule COCl₂ is:
→ Polar
Explanation
COCl₂, or phosgene, consists of a central carbon atom bonded to two chlorine atoms and one oxygen atom via a double bond. The Lewis structure reflects this with a double bond to oxygen (O=C) and single bonds to each Cl. Oxygen has two lone pairs, and each chlorine atom has three lone pairs.
The carbon atom in COCl₂ has three electron domains (two single bonds and one double bond), which adopt a trigonal planar geometry to minimize electron-pair repulsion, according to VSEPR theory (Valence Shell Electron Pair Repulsion). This results in bond angles of approximately 120°, which is typical of trigonal planar molecules.
Each C–Cl bond is polar due to the difference in electronegativity between carbon (2.55) and chlorine (3.16). Similarly, the C=O bond is highly polar, with oxygen (3.44) being more electronegative than carbon. While the molecule has a symmetrical shape, the differing strengths and directions of the bond dipoles (especially the stronger C=O dipole) cause COCl₂ to have a net dipole moment, making the molecule polar overall.
Regarding the comparison molecules:
- CO₂ is linear and symmetrical, making it non-polar despite polar bonds.
- SO₂ is bent due to lone pairs on sulfur, making it polar.
- PCl₃ has a trigonal pyramidal shape due to a lone pair on phosphorus, creating an asymmetrical charge distribution — hence polar.
- CH₂Cl₂ (dichloromethane) is tetrahedral, and the unequal distribution of Cl and H atoms makes it polar as well.
In summary, COCl₂ is a polar, trigonal planar molecule with 120° Cl–C–Cl bond angles and polar C–Cl bonds.
