Answer to Question #53678 in Inorganic Chemistry for Najirul haq

Question

between H2O and H2O2 which has higher boiling point and why?

Answer 1

H2O2 has boiling point 1500C, water 1000C
While boiling point differences can be attributed to variations in the strengths of intermolecular forces, there are three types of forces which must be considered.
Hydrogen peroxide has more electrons, which gives a greater polariability for H2O2 and stronger London dispersion forces.
H2O2 has a much greater dipole moment than does water. H2O2 is 2.26 Debye vs 1.86 Debye for water. The greater dipole-dipole attraction also contributes to the increased boiling point.
H2O2 exibits hydrogen bonding and with one additional oxygen atom, compared to water, there are more sites available to form hydrogen bonds. With potentially more hydrogen bonding in H2O2, the boiling point will be greater.
The bottom line is that all three types of intermolecular forces are stronger for hydrogen peroxide than for water which accounts for the greater boiling point of H2O2.