What properties of water make it useful as a solvent? What types of compound can it $(i)$ dissolve,and $(ii)$ hydrolyse?

Water is a universal solvent primarily due to its high dielectric constant $(78.39 \, C^{2} / Nm^{2})$ and high dipole moment.
$(i)$ Water dissolves ionic compounds through ion-dipole interactions and covalent compounds that are capable of forming hydrogen bonds with water.
$(ii)$ Water hydrolyzes various compounds including metallic and non-metallic oxides,hydrides,carbides,phosphides,and nitrides. During hydrolysis,the $H^{+}$ and $OH^{-}$ ions of water react with the substrate.
Examples of hydrolysis reactions:
$CaO + H_{2}O \longrightarrow Ca(OH)_{2}$
$NaH + H_{2}O \longrightarrow NaOH + H_{2}$
$CaC_{2} + H_{2}O \longrightarrow C_{2}H_{2} + Ca(OH)_{2}$