%X In this study, the Henry's Law constant and the activity coefficients in infinite dilution in a mass fraction of (25 and 50) of methyldiethanolamine (MDEA) aqueous solution within the temperature range of (298 to 348) K at atmospheric pressure, were measured. An inert gas stripping method was used to perform all the measurements. The new values of Henry's Law constant and the activity coefficients in infinite dilution correlation with solute molecular size were explained. The influence of the solvent is discussed taking into consideration the heat of absorptions for different MDEA concentrations. Experimental results are compared to literature data wherever available. © 2015 Elsevier Ltd. %K Activity coefficients; Atmospheric pressure; Solubility; Solutions, Heat of absorptions; Heat of solution; Henry's Law constant; Infinite dilution; Infinite dilution activity coefficients; Limiting activity coefficient; Methyldiethanolamine; Temperature range, Inert gases %L scholars7228 %J Journal of Chemical Thermodynamics %O cited By 5 %R 10.1016/j.jct.2015.10.005 %D 2016 %V 93 %I Academic Press %A R.M. Zin %A C. Coquelet %A A. Valtz %A M.I. Abdul Mutalib %A K.M. Sabil %T Measurement of Henry's Law constant and infinite dilution activity coefficient of isopropyl mercaptan and isobutyl mercaptan in (methyldiethanolamine (1) + water (2)) with w1 = 0.25 and 0.50 at temperature of (298 to 348) K using inert gas stripping method %P 193-199