Abstract The kinetics of hydrolysis reactions of some chlorodisiloxanes and of the chloropentasiloxanes (Me 3) SiO) 2 Si (Me) OSiAr (Cl) OSiMeAr′(with Ar= Ph and Ar′= p- ClC 6 H 4, C 6 H 5 or p-MeC 6 H 4; or Ar′= Ph and Ar= p-ClC 6 H 4, C 6 H 5 or p-MeC 6 H