Question

In which of the following molecules/ions, are all the bonds not equal?

• A. NF\(_3\)
• B. NH\(_4^+\)
• C. AgCl
• D. CH\(_4\)

Hint:

In molecules with lone pairs on the central atom (like NF\(_3\)), the bonds may not be equal due to differences in electron repulsion. In symmetrical molecules like NH\(_4^+\) and CH\(_4\), the bonds are equal.

Answer 1

The Correct Option is A

To identify the molecule or ion with unequal bonds, we analyze each option:

• NF\(_3\): Nitrogen trifluoride has a trigonal pyramidal structure. The N-F bonds are polar. The lone pair on nitrogen disrupts electron distribution, leading to unequal bond angles.
• NH\(_4^+\): The ammonium ion has a tetrahedral shape. All N-H bonds are equivalent, resulting in equal bond lengths and angles.
• AgCl: Silver chloride is an ionic compound (Ag\(^+\) and Cl\(^-\)) and lacks multiple bonds for comparison.
• CH\(_4\): Methane has a perfect tetrahedral shape. All C-H bonds are identical, resulting in equal bonds.

In conclusion, NF\(_3\) has unequal bonds due to its asymmetric shape and the nitrogen atom's lone pair, which affects bond angles and lengths.