(a) Define the so-called 'colligative' properties, and write brief notes about each of them.
(b) A system comprises two liquid components. State whether the system would be likely to display positive deviation from ideality, approximate ideality, or negative deviation, if:
(i) the Henry's law constants are larger than the Raoult constants for both components;
(ii) the Henry's law constants are approximately equal to the Raoult constants for both components;
For clarity, sketch the overall profile of total vapour pressure with system composition for answers (i) and (ii) above.
(c) An osmotic molecular-weight determination for a large polymer dissolved in benzene resulted in the following data:
Amount dissolved in 250 ml benzene solution
exactly 1.5 g
exactly 1.0 g
exactly 0.5 g
Write down the van't Hoff equation applicable to this situation, and estimate the molar mass of the dissolved polymer.