New experimental vapor pressures and vaporization enthalpies of the ionic liquids [C(n)mim][CH3SO3] (with the alkyl chain length n = 2, 3 and 4) have been measured by the QCM and TGA methods. Energies of combustion of [C(2)mim][CH3SO3] and [C(4)mirn][CH3SO3] were measured in a high-precision rotating-bomb combustion calorimeter and used for calculation the aqueous enthalpy of formation of the Delta H-f(m)0 (CH(3)SO(3)i(4))anion. The solubility parameters of ILs under study have been derived from experimental Delta H-g(1)m(0)(298.15 K) and used for estimation of miscibility of some common solutes in [C(n)mim][CH3SO3]. This comprehensive thermodynamic study will facilitate chemical engineering calculations of processes involving ionic liquids. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.