The rate constants have been measured of alkaline solvolysis of the Si-H bond of trisubstituted silanes Rn (CH3h_nSiH [where R=(CH3hSiO-,(CH3hCO-,(CH3hCCH2-; Il= 0 to 3],[(CH3hSiOlnC2HS (CH3) 2_nSiH (Il= 0 to 2) and (C2HsO\(C3H7h-n SiH (Il= 0 to 3). The results of solvolysis of silanes with oxygenous substituents could not be explained in terms of only the polar or steric effects of the substituents. The paper presents a discussion of the ...