MHTCET 18 Apr 2026 Shift 2 Paper

Concept:The dipole moment of a molecule depends on the direction and magnitude of bond dipoles and the lone-pair dipole on the central atom.Explanation:Both $\mathrm{NH}_{3}$ and $\mathrm{NF}_{3}$ have one lone pair on nitrogen, so both have a pyramidal shape.In $\mathrm{NH}_{3}$, nitrogen is more electronegative than hydrogen, so the N–H bond dipoles point toward nitrogen.The resultant of these three bond dipoles points in the same direction as the lone-pair dipole.This makes the net dipole moment of $\mathrm{NH}_{3}$ relatively large.In $\mathrm{NF}_{3}$, fluorine is more electronegative than nitrogen, so the N–F bond dipoles point toward fluorine.Therefore, the resultant bond dipole is opposite to the lone-pair dipole on nitrogen.These opposite directions cancel partially, giving $\mathrm{NF}_{3}$ a much smaller dipole moment.Thus, the statement that the lone-pair dipole and the resultant bond dipole are in the same direction in both $\mathrm{NH}_{3}$ and $\mathrm{NF}_{3}$ is false.Answer:Option C is the incorrect statement.