Question

(a) Define the following terms:
(i) Ideal solution (ii) Azeotrope (iii) Osmotic pressure
(b) A solution of glucose $\left(C_6{H}_{12}{O}_6\right)$ in water is labelled as $10$% by weight. What would be the molality of the solution?
(Molar mass of glucose $=180g/mol$)

Answer 1

(a) i. Ideal solution is that solution which follows Raoult's law. An ideal solution or ideal mixture is a solution in which the enthalpy of solution ( $\Delta H_{solution},\Delta V_{solution},\Delta S_{solution}$ is 0 ,with the closer to zero the enthalpy of solution, the more "ideal" the behavior of the solution becomes
ii. An azeotrope or a constant boiling mixture is a mixture of two or more liquids whose proportions cannot be altered by simple distillation. This happens because when an azeotrope is boiled, the vapour has the same proportions of constituents as the unboiled mixture.
iii. Osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane. It is also defined as the measure of the tendency of a solution to take in water by osmosis.
b. Molality= $\frac{percent\left(w/w\right)}{molmass}\times \frac{1000}{100\%\left(w/w\right)}$
=$\frac{10}{180}\times \frac{1000}{100-10}$
=6.17 m