Properties
The boiling point of H
2O
2 has been extrapolated as being 150.2 °C, approximately 50 degrees higher than water; in practice hydrogen peroxide will undergo potentially explosive thermal decomposition if heated to this temperature. It may be safely distilled at lower temperatures under reduced pressure.[5]
In aqueous solutions
In aqueous solutions hydrogen peroxide differs from the pure material due to the effects of hydrogen bonding between water and hydrogen peroxide molecules. Hydrogen peroxide and water form a eutectic mixture, exhibiting freezing-point depression; pure water has a melting point of 0 °C and pure hydrogen peroxide of −0.43 °C, but a 50% (by volume) solution of the two freezes at -51 °C. The boiling point of the same mixtures is also depressed in relation with the median of both boiling points (125.1 °C). It occurs at 114 °C. This boiling point is 14° greater than that of pure water and 36.2° less than that of pure hydrogen peroxide.[6]