Question

Which of the following molecules has a linear shape?

• A. H\(_2\)O
• B. CO\(_2\)
• C. NH\(_3\)
• D. SO\(_2\)

Hint:

Key Fact: A molecule with two bonded atoms and no lone pairs on the central atom is linear.

Answer 1

The Correct Option is B

Molecular geometry determines if a molecule is linear. VSEPR theory states that electron pair repulsion (bond pairs and lone pairs around the central atom) dictates this geometry.

Analysis of each molecule:

• H₂O: Oxygen, bonded to two hydrogens and possessing two lone pairs, results in a bent shape due to electron repulsion, not linear.
• CO₂: Carbon, double-bonded to two oxygens with no lone pairs, exhibits a linear shape due to symmetrical bond distribution.
• NH₃: Nitrogen, bonded to three hydrogens and having one lone pair, forms a trigonal pyramidal shape, not linear.
• SO₂: Sulfur, bonded to two oxygens and possessing a lone pair, adopts a bent shape, not linear.

Therefore, CO₂ is the linear molecule.