The vapour pressure of a solvent is lowered by the presence of the non-volatile solute in the solution and this lowering of vapour pressure of the solvent is governed by Raoult's law , according to which the relative lowering of vapour pressure of the solvent over a solution is equal to the mole fraction of a non-volatile solute present in the solution. Howerver, in a case of binary liquid solution, if both the components of the solution are volatile then another from of Raoult's law is used . Mathematically, this from of the Raoult's can be given as: `P_("total"=P_(1)^(0)X_(1)+P_(2)^(0)X_(2)`.
Solution which obey Raoult's law over the entire range of concentration are known as ideal solution . two types of deviation from Raoult's law, that is, positive and negative deviations are observed. Azeotrons arise due to very large deviation from Raoult's law .
(When a plot of boiling point versus composition is plotted, then the type of grapgh that cannot be obtained is
Select the correct option for an ideal solution :
(i) `Delta_("mix")=0, DeltaV_("mix")=0`
(ii) `DeltaS_("mix")gt 0, DeltaV=0`
(iii) `DeltaH_("mix")=0, DeltaSgt0`
(iv) V. Pobs gt. V. P exp.

Options

A. I,ii,iii,iv
B. I,ii,iii
C. ii,iii,iv
D. I,ii

Answer

B