Question

Which of the following pairs of compounds lists the molecule with the stronger dipole–dipole forces first? CH2Br2 and CH2Cl2 C3H8 and CH3CN (CH3)3N and (CH3)3P (CH3)2S and (CH3)2O CH3F and CHF3 Previous Next

Answer 1

A) Br is less electronegative than Cl as it lies below Cl in the periodic table. So will have less dipole moment than as the difference in electronegativities of H and Cl is more than difference in electronegativities of H and Br. Thus CH₂Cl₂​ has stronger dipole-dipole forces.

B) is a non-polar molecule whereas is polar. This is because there is not much difference in electronegativities of H and C but there is a lot of difference in electronegativities of C and N. So CH₃​​​​CN has stronger dipole-dipole forces.

C) N has more electronegativity than P as P lies below N in the periodic table. So has more dipole moment than . Thus has stronger dipole-dipole forces.

D) O has more electronegativity than S as it lies above S in the periodic table. So has less dipole moment than and hence has stronger dipole-dipole forces.

E) has only one F whereas has 3 F. So the dipole moment of is more than that of . Thus has stronger dipole-dipole forces.