(a) Hydrogen peroxide can be made by adding a metal peroxide to dilute acid.
BaO2(s) + H(s)SO4 → BaSO4(s) + H2O2(aq)
(b) Structure of H2O2
(i). H2O2 has a non-polar structure. The molecular dimensions in the gas phase and solid phase differ as shown in the figure.
(ii). Both in gas phase and solid phase, the H2O2 molecule adopt a skew configuration due to repulsive interaction of the – OH bonds with lone pairs of electrons on each oxygen atom.
(iii). Indeed, it is the smallest molecule known to show hindrance rotation about a single bond. in solid phase, the dihedral angle is sensitive and hydrogen bonding decreasing from 111.50 in the gas phase to 90.2°, in the solid phase.
(iv). Structurally, H2O2 is represented by the dihydroxyl formula in which the two O-H groups do not lie in the same plane. In the solid phase of molecule, the dihedral angle reduces to 90.2° due to hydrogen bonding and the O-O-H angle expands from 94.8° to 101.9°.
(v). One way of explaining the shape of hydrogen peroxide is that the hydrogen atoms would lie on the pages of a partly opened book, and the oxygen atoms along the spin.