JEE Main 2025 — Chemical Bonding And Molecular Structure Question with Solution

We need to compare the experimental (or well‐established) dipole moments of the given molecules: $\mathrm{HBr},{\mathrm{H}}_2\mathrm{S},\mathrm{N}{\mathrm{F}}_3,$ and $\mathrm{CHC}{\mathrm{l}}_3$.

---

1. $\mathbf{N}{\mathbf{F}}_3$

Structure: Trigonal pyramidal (like $\mathrm{N}{\mathrm{H}}_3$), but each bond is more polar toward fluorine.

Net dipole moment: Quite small, about $0.23\text{–}0.24D$ (the bond dipoles partly oppose the lone‐pair contribution).

2. $\mathbf{HBr}$

Structure: Simple diatomic.

Dipole moment: About $0.78D$.

3. ${\mathbf{H}}_2\mathbf{S}$

Structure: Bent (like ${\mathrm{H}}_2\mathrm{O}$) but S is less electronegative than O, and the S–H bond angle is wider than the O–H angle in water.

Dipole moment: About $0.95D$.

4. $\mathbf{CHC}{\mathbf{l}}_3$ (chloroform)

Structure: Tetrahedral around carbon with three Cl and one H.

Dipole moment: About $1.01D$.

---

Ordering from smallest to largest dipole moment

$\boxed{\mathrm{N}{\mathrm{F}}_3<\mathrm{HBr}<{\mathrm{H}}_2\mathrm{S}<\mathrm{CHC}{\mathrm{l}}_3.}$

Hence, the correct choice is:

$\boxed{\text{Option (C)}N{F}_3<HBr<H_{2}S<CHC{l}_3.}$