Question

Which one of the following pairs is an example of polar molecular solids ?

• A. HCl (s), AlN (s)
• B. MgO (s), SO₂(s)
• C. SO₂(s), NH₃(s)
• D. SO₂(s), CO₂(s)

Answer 1

The Correct Option is C

Polar molecular solids are formed by polar molecules held together by dipole-dipole interactions. Let us analyze the given compounds:

• \( \text{SO}_2 \): \( \text{SO}_2 \) has a bent structure with a net dipole moment, making it a polar molecule. It forms polar molecular solids.
• \( \text{NH}_3 \): \( \text{NH}_3 \) has a trigonal pyramidal structure and a net dipole moment, making it polar. It also forms polar molecular solids.
• \( \text{CO}_2 \): \( \text{CO}_2 \) is linear and nonpolar, so it does not form polar molecular solids.
• \( \text{MgO} \): \( \text{MgO} \) is an ionic solid and does not belong to polar molecular solids.
• \( \text{HCl} \): \( \text{HCl} \) is a polar molecule and can form polar molecular solids.
• \( \text{AlN} \): \( \text{AlN} \) is an ionic solid and does not form polar molecular solids.

Conclusion:

Final Answer: The pair \( (\text{SO}_2(s), \text{NH}_3(s)) \) is an example of polar molecular solids.