26. Use the example of a solution of benzene in toluene to explain what is meant by an ideal solution 27. What characteristic of a solution determines its colligative properties? 28, The vapour pressure of ethanol (C, H,OH) and 1-propanol (C, H,OH) at 35°C are 100 mmHg and 37.6 mmHg, respectively. Assuming ideal behaviour, calculate the partial vapour pressures of ethanol and l-propanol over a solution, in which the mole fraction of ethanol is 0.3. 2. A solution was made by dissolving 3.75 g of a pure non-volatile solute in 95 g of acetone. The boiling point of pure acetone was observed to be 55.95°C, and that of the solution was 56.50°C. If the molar boiling point elevation constant (K) of acetone is 1.71°C kg/mol, what is the approximate molar mass of the solute?