Colliga Henry's constant for the gas and the solubility at 25 C and 5.0 atm. 7. Calculate: (i) the vapor pressure of a mixture of benzene and toluene at 25 °C if the mole fraction of benzene in the mixture is 0.495, and; (ii)the mole fraction benzene and toluene in the vapor (At 25 C, the vapor pressure of benzene is 96.0 mm Hg and 30.3 mm Hg for toluene) 8. Calculate the vapor pressure of a solution of 1.0 mol of sucrose dissolved in 15.0 mol of water at 25°C. The vapor pressure of water at 25°C 23.76 mm Hg. 9. A solution of 1.10 g of benzoic acid in 8.50 g of lauric acid had a freezing point of 38.5 °c. what is the molar mass of benzoic acid? The freezing point of lauric acid is 44.0â and kr is 3.60°C. kg/mol. 10. (a) Tell what is meant by: (G) osmosis (ii) osmotic pressure (lii)reverse osmosis; and (b) Calculate the osmotic pressure of a 0.150 M aqueous solution of CaCl at 25 C