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

To determine which molecule has a linear shape, we need to consider the molecular geometry. Molecular geometry is influenced by the number of bond pairs and lone pairs of electrons around the central atom, according to VSEPR (Valence Shell Electron Pair Repulsion) theory.

Let's analyze each molecule: 

• H₂O: Water has two hydrogen atoms bonded to an oxygen atom. Oxygen has two lone pairs of electrons. The molecular shape is bent due to electron pair repulsion, not linear.
• CO₂: Carbon dioxide consists of a carbon atom double-bonded to two oxygen atoms. No lone pairs on the carbon. The bonds are distributed symmetrically, resulting in a linear shape.
• NH₃: Ammonia has three hydrogen atoms bonded to a nitrogen atom with one lone pair, giving it a trigonal pyramidal shape, not linear.
• SO₂: Sulfur dioxide consists of a sulfur atom bonded to two oxygen atoms and has a lone pair, leading to a bent shape, not linear.

Based on this analysis, CO₂ is the molecule with a linear shape.