Due to high dielectric constant, it has a very strong hydrating tendency. It dissolves many ionic compounds. However, certain covalent and some ionic compounds are hydrolysed in water.Examples-
P4 O10 (s) +6H2 O ----------> 4H3 PO4( aq)
SiCl 4 +2H2 O ----------> SiO2( s) + 4HCl