The Lewis structures of four compounds are given. O=S=O O=C=O H-C(Cl)H-Cl Cl-P(Cl)-Cl Which of these molecules are polar? SO2 PCl3
Answer (1)
To determine which molecules are polar among the given options, it's important to understand the concept of molecular polarity. A polar molecule is one with an uneven distribution of electron density, resulting in a dipole moment. This occurs when there is a difference in electronegativity between the bonded atoms and an asymmetrical shape that doesn't cancel out the dipole.
Let's examine the two molecules in question:
SO 2 (Sulfur Dioxide):
Structure: SO 2 has a bent or V-shaped molecular structure due to the presence of a lone pair on the sulfur atom.
Electronegativity: Oxygen is more electronegative than sulfur, which creates polar bonds (S=O).
Polarity: The bent shape ensures that the dipoles do not cancel out, making SO 2 a polar molecule.
PCl 3 (Phosphorus Trichloride):
Structure: PCl 3 has a trigonal pyramidal shape due to the lone pair present on the phosphorus atom.
Electronegativity: Chlorine is more electronegative than phosphorus, resulting in polar P-Cl bonds.
Polarity: The trigonal pyramidal shape leads to an uneven distribution of electron density, making PCl 3 a polar molecule.
Therefore, both SO 2 and PCl 3 are polar molecules due to their shape and the differences in electronegativity between bonded atoms.
