VLECalc - Version 1.3 VLECalc is a tool for chemists and engineers who develop chemical manufacturing processes that use organic chemicals and solvents. It can estimate the vapor pressure and boiling point of a mixture containing up to 6 components. It can simulate a simple batch distillation/solvent replacement operation. Either UNIFAC or NRTL thermodynamics may be used. Calculation results are captured by Microsoft Excel 97. An Excel database of commonly used chemicals/solvents is included. A full description with screen shots is available at http://www.vlecalc.org