Same chapter3 marksDifficulty: Medium
Explain why carbon dioxide is non-polar although each C=O bond is polar.
Chemical Bonding and Molecular Structure
3 marksDifficulty: Medium
Using VSEPR theory, predict the shape of BF3, NH3 and H2O and give the reason for the difference.
Original Khojo Papers practice question — not from a past board paper.
Answer
BF3 is trigonal planar with bond angles of 120° and no lone pairs. NH3 is trigonal pyramidal with an angle of about 107°, because one lone pair pushes the bonds together. H2O is bent with an angle of about 104.5°, because two lone pairs push them together still more.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Lone pair repulsion is stronger than bond pair repulsion, so each lone pair narrows the bond angle.
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