(i) Ice formed by heavy water sinks in normal water due to higher density of ${\mathrm{D}}_2\mathrm{O}$ than normal water

(ii) $6\mathrm{C}{\mathrm{O}}_2+6{\mathrm{H}}_2\mathrm{O}\stackrel{\mathrm{h}\mathrm{v}\mathrm{c}\mathrm{h}\mathrm{l}\mathrm{o}\mathrm{r}\mathrm{o}\mathrm{p}\mathrm{h}\mathrm{y}\mathrm{l}\mathrm{l}}{\to }{\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6+6{\mathrm{O}}_2$

(iii) Water can show amphiprotic nature and hence water can act both as an acid a base

(iv) There is extensive intermolecular hydrogen bonding in the condensed phase instead of intramolecular H-bonding