A spreadsheet-based project is presented that is designed to enhance and expand student understanding of phase transition properties of pure water and ideal and nonideal (electrolyte) aqueous solutions. Using fundamental principles of classical and statistical thermodynamics, students calculate the melting and boiling points, the enthalpies and entropies of fusion and vaporization of pure water, and the freezing point depression and boiling point elevation of ideal and nonideal aqueous solutions. The results of the calculations are in good agreement with literature values. Complete details are provided in the Supporting Information.