Question

Among the following, the molecule with highest dipole moment is :

• A. $C{H}_{3}Cl$
• B. $C{H}_{2}C{l}_2$
• C. $CHC{l}_3$
• D. $CC{l}_4$

Answer 1

The correct option is A $C{H}_{3}Cl$

The correct option (a) $C{H}_{3}Cl$

Explanation:

The dipole moment of a polar molecule depends upon its geometry. The asymmetrical molecule is non-polar even though it contains polar bonds. Methane molecule ($C{H}_4$) has zero value of dipole moment due to its symmetric structure. We know that the bond dipole moment of $C-H$ bond of $C-Cl$ bond reinforces one another. In $CHC{I}_3$, the resultant of C-H and C-Cl dipoles oppose the resultant of two C-Cl dipoles while in $C{H}_{2}C{l}_2$, the resultant of C-H dipoles adds to resultant of two C-Cl. In case $C{H}_{3}Cl$, the resultant of two C-H dipoles adds to the resultant of two C-Cl. In case $C{H}_{3}CI$, the resultant of two C-H dipoles add to the resultant of C- H and C- Cl dipoles. Thus, the dipole moment of CH3CI is highest among the given compounds. The molecule ($CC{l}_4$) again becomes symmetrical and the dipole moment reduces to zero.