Which of the following pairs exhibit only dispersion forces as the only intermolecular forces ?

Options

A. `HBr` and `H_(2)S`
B. `NH_(3)` and `C_(6)H_(6)`
C. `Cl_(2)` and `CBr_(4)`
D. `I_(2)` and `NO_(3)^(-)`

Answer

C

Explanation

Both `Cl_(2)` and `CBr_(4)` are nonpolar, so there are only dispersion forces between these molecules . Both `HBr` and `H_(2)S` are polar , so the forces between them are dipole -dipole forces. There are also dispersion forces between the molecules. `I_(2)` is nonpolar, so the forces between it and the ion `NO_(3)^(-)` are ion-induced forces and dispersion forces.
`NH_(3)` is polar and `C_(6)H_(6)` is nonpolar. The forces are dipole-induced dipoel forces and dispersion forces.