Question

The bond angle is maximum in which of the following molecules?

• A. ${H_2O} $
• B. ${NH_3}$
• C. ${CH_4}$
• D. ${CO_2}$

Hint:

Bond Angle Trends.

• Lone pairs reduce bond angle due to stronger repulsion.
• Tetrahedral (sp$^3$): $109.5^\circ$, Trigonal pyramidal: $109.5^\circ$, Bent: $<107^\circ$.
• Linear (sp): $180^\circ$ is maximum.

Answer 1

The Correct Option is D

Bond angles are influenced by hybridization and lone pair repulsions. Let's analyze each option:

• \( \mathrm{H_2O} \): Bent shape with 2 lone pairs on oxygen. Bond angle is \( \approx 104.5^\circ \) due to lone pair–lone pair repulsion.
• \( \mathrm{NH_3} \): Trigonal pyramidal shape with 1 lone pair on nitrogen. Bond angle is \( \approx 107^\circ \).
• \( \mathrm{CH_4} \): Tetrahedral shape. Bond angle is \( 109.5^\circ \).
• \( \mathrm{CO_2} \): Linear molecule with sp hybridization. Bond angle is \( 180^\circ \).

Clearly, \( \mathrm{CO_2} \) has the maximum bond angle among the given molecules.

Answer 2

Step 1: Understand bond angles and molecular geometry
Bond angles in molecules depend on the arrangement of atoms around the central atom, which is determined by the molecular geometry. The ideal bond angle is influenced by the type of electron pair repulsions according to VSEPR theory.

Step 2: Analyze CO₂ molecule
CO₂ is a linear molecule with the central carbon atom bonded to two oxygen atoms. The bond angle in CO₂ is 180°, which is the maximum possible bond angle between two atoms.

Step 3: Compare with other molecules
Other molecules like H₂O, NH₃, or BF₃ have bond angles less than 180° due to lone pair repulsions or trigonal planar structures.

Step 4: Conclusion
Therefore, among the given options, CO₂ has the maximum bond angle of 180° due to its linear shape.