Answer:
CO2 < CH3Br < CH3OH < RbF
Explanation:
The boiling point of the compounds can be determined in terms of the strength of the intermolecular forces present in each compound.
Intermolecular forces are weak forces joining non-polar and polar molecules together. We have London dispersion forces, dipole-dipole forces of attraction, and hydrogen bonding.
London dispersion forces are weak attractions found between non-polar and polar symmetrical molecules. They are the weakest of all the electrical forces and they act between atoms and molecules e.g CO2
The dipole-dipole attractions are forces of attraction existing between polar unsymmetrical molecules. The dipole-dipole force of attractions is much stronger than London dispersion forces but weaker than Hydrogen bonding. e.g CH3Br
Hydrogen bonding is a special dipole-dipole attraction between polar molecules in which a hydrogen atom is directly joined to a highly electronegative atom (e.g. oxygen, nitrogen, or fluorine). Here, the bond in CH3OH is a hydrogen bond.
Ionic bonding is a bond that is formed between two kinds of atoms having a large electronegative difference such as in RbF,
Thus, in increasing order of boiling point;
CO2 < CH3Br < CH3OH < RbF
