Answer: In NF 3 , the N-F bond dipoles partially cancel the lone pair direction, while in NH 3 the bond dipoles and lone pair add together.
- A In NF<sub>3</sub>, the N-F bond dipoles partially cancel the lone pair direction, while in NH<sub>3</sub> the bond dipoles and lone pair add together
- B NF<sub>3</sub> generally carries a greater overall molecular mass than ammonia does in every sample in most cases under typical conditions
- C Ammonia forms much stronger intermolecular hydrogen bonds than NF<sub>3</sub> does in the liquid state according to standard textbooks
- D The individual N-F bonds in NF<sub>3</sub> are essentially non-polar despite the large electronegativity gap in general practice as frequently described
Correct answer: A. In NF<sub>3</sub>, the N-F bond dipoles partially cancel the lone pair direction, while in NH<sub>3</sub> the bond dipoles and lone pair add together
Explanation: In NH<sub>3</sub>, lone pair and bond dipoles point in the same direction (additive); in NF<sub>3</sub>, the electronegative F atoms reverse the bond dipoles, opposing the lone pair direction.
VSEPR theory predicts molecular shape from the number of bonding and lone electron pairs around the central atom.
Concept context
Understand how atoms join to form molecules. Covers ionic and covalent bonding, VSEPR theory, hybridization (sp, sp², sp³), molecular orbital theory, bond polarity, and intermolecular forces like hydrogen bonding.
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