The dipole moments of $\mathrm{CCl}_{4}$, $\mathrm{CHCl}_{3}$ and $\mathrm{CH}_{4}$ are in the order

(C) $\mathrm{CH}_{4}=\mathrm{CCl}_{4}<\mathrm{CHCl}_{3}$

(A) $\mathrm{CHCl}_{3}<\mathrm{CH}_{4}=\mathrm{CCl}_{4}$

(B) $\mathrm{CCl}_{4}<\mathrm{CH}_{4}<\mathrm{CHCl}_{3}$

(D) $\mathrm{CH}_{4}<\mathrm{CCl}_{4}<\mathrm{CHCl}_{3}$

JEE Main · 2020 · 07 Jan 2020 · Shift 1 · Chemical Bonding and Molecular Structure

The dipole moments of

CCl_{4}

CHCl_{3}

and

CH_{4}

are in the order

Answer: (C)

A dipole moment survives only if the bond polarities fail to cancel. Both

C H_{4}

and

CC l_{4}

are regular tetrahedra whose four identical bonds cancel exactly, giving zero moment, while

CHC l_{3}

has three Cl and one H, so its pulls do not balance and it carries a net moment. The order is thus

C H_{4} = CC l_{4} < CHC l_{3}

JEE Main · 2020 · 07 Jan 2020 · Shift 1 · Single correct option