Isobaric vapor-liquid equilibrium data at an atmospheric pressure of 95.5 kPa are reported for the binary systems 2-methyl propan-2-ol (1) + tetraethoxylsilane (2) and 2-methyl propan-2-ol (1) + 1-phenyl ethanone (2). The experiments are done using a Swietoslawski-type ebulliometer. The liquid-phase mole fraction, x(1), versus bubble-point temperature, T, measurements are found to be well-represented by the Wilson model. The optimum Wilson parameters are used to calculate the vapor-phase composition, activity coefficients, and excess Gibbs free energy. The results are discussed.