Liquid–liquid equilibria of binary systems containing a room-temperature ionic liquid (1-butyl-3-methylimidazolium 2-(2-methoxyethoxy)-ethylsulfate [BMIM][MDEGSO₄], with: a hydrocarbon (n-hexane, cyclohexane, or benzene); a ketone (pentan-3-one, nonan-5-one or cyclopentanone); an alcohol (methanol, ethanol, butan-1-ol or octan-1-ol); 1,1-dimethylpropyl methyl ether or water were measured at normal pressure by a dynamic method from 287 K to the boiling point of the solvent or to 373 K. This paper includes thermophysical basic characterization of pure ionic liquid, obtained via differential scanning calorimetry (DSC), temperature of decomposition, temperature of glass phase transition, and heat capacity at half the C_p extrapolated temperature. The solubility of [BMIM][MDEGSO₄] in ketones decreases with an increase of the molecular weight of the ketone and is much higher in cycloketones than in a linear ketone. The solubility of the investigated IL is higher in aromatic hydrocarbons than in cyclic or linear hydrocarbons with the same number of carbon atoms. As a result of its strong interactions with alcohols, [BMIM][MDEGSO₄] shows complete miscibility with methanol, ethanol, butan-1-ol and octan-1-ol above 293 K. The experimental results of LLE have been correlated using the binary parameters of the non-random two liquid (NRTL) equation. The average root-mean-square deviation for the equilibrium mole fraction for all the calculated values was found to be 0.0031.