In which of the following groups of substances would dispersion forces be the only significant factors in determining boiling points? I. Cl2II. HFIII. NeIV. KNO2V. CCl4

Cl2, Ne, CCl4 are the group of substances in which dispersion forces would

help determine the boiling point.

Dispersion force  is a type of Van der waals force and is also regarded as

London forces. This type of force occur between the atoms and molecules

when electrons are symmetrically distributed in the nucleus.

This force is a weak intermolecular force and is present in non polar

compounds such as Cl2, Ne, CCl4 . KNO2 is polar and hence doesn't

determine its boiling point.

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Cl2,Ne, CCl4

Explanation:

Dispersion forces are quite significant as the predominant intermolecular forces in nonpolar substances. For Cl2,Ne and CCl4, dispersion forces are the primary kind of intermolecular interaction present in the compound.

Hence, the boiling point of these substances will be determined solely by the dispersion forces between the molecules.