(N/A) Concentration of $H_2O_2$: The $H_2O_2$ solution obtained industrially is about $30\%$ by mass. It can be concentrated to $\sim 85\%$ by careful distillation under reduced pressure. The remaining water can be frozen out to obtain pure $H_2O_2$.
Structural Differences:
- $H_2O$ has a bent (angular) structure with a bond angle of $104.5^\circ$ and $O-H$ bond length of $95.7 \text{ pm}$.
- $H_2O_2$ has a non-planar 'open book' structure. In the gas phase, the dihedral angle is $111.5^\circ$, and in the solid phase, it is $90.2^\circ$.
Uses of $H_2O_2$:
$1$. It is used as an antiseptic and mouthwash (sold as perhydrol).
$2$. It is used in the manufacture of chemicals like sodium perborate and sodium carbonate.
$3$. It is used as a bleaching agent for textiles, paper pulp, and oils.