Liquid-liquid solutions are considered ideal if their vapor pressures obey Raoult’s law. A liquid-liquid solution composed of 0.54 water and 0.46 propanol (C3H7OH), in mole fractions, has a vapor pressure of 81.6 torr at 45oC. The vapor of pure water and pure propanol at 45oC is 71.9 torr and 74.0 torr, respectively. Determine whether the above water-propanol solution is ideal, non-ideal with a positive deviation, or non-ideal with a negative deviation. Explain.            (A) Ideal solution; the observed vapor pressure of 81.6 torr is equal to the calculated vapor pressure.           (B) Non-ideal with positive deviation; the observed vapor pressure is higher than calculated.           (C) Non-ideal with negative deviation; the calculated vapor pressure is higher than observed.           (D) Non-ideal with positive deviation; the calculated vapor pressure is lower than observed.

1. Liquid-liquid solutions are considered ideal if their vapor pressures obey Raoult’s law. A liquid-liquid solution composed of 0.54 water and 0.46 propanol (C₃H₇OH), in mole fractions, has a vapor pressure of 81.6 torr at 45^oC. The vapor of pure water and pure propanol at 45^oC is 71.9 torr and 74.0 torr, respectively. Determine whether the above water-propanol solution is ideal, non-ideal with a positive deviation, or non-ideal with a negative deviation. Explain. 

          (A) Ideal solution; the observed vapor pressure of 81.6 torr is equal to the calculated vapor pressure.

          (B) Non-ideal with positive deviation; the observed vapor pressure is higher than calculated.

          (C) Non-ideal with negative deviation; the calculated vapor pressure is higher than observed.

          (D) Non-ideal with positive deviation; the calculated vapor pressure is lower than observed.