Suppose you were calibrating a 100.0 ml volumetric flask using distilled water. the flask temperature was at 20°c, and you assumed that the distilled water was as well. however, you later discover that the actual water temperature was 12°c instead. how is the mass of the 100.0 ml of distilled water you measured at 12°c different from the mass of 100.0 ml of distilled water at 20°c?

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.