Experimental measurements are reported for total and partial heats-of-vaporization for the n-propane/n-decane system. Results are given for the 100, 130 and 160°F. isotherms and cover the entire composition range. It is shown that the temperature and concentration gradients which develop within the system during the vaporization process may, in some cases, cause a significant (~0.4%) deviation in the calculated results. A method is provided for introducing a correction for this effect. Based on the partial heat-of-vaporization of n-propane, heats-of-mixing for the liquid solution are calculated. The results are in qualitative agreement with predictions from theories for n-alkane liquid mixtures.