At 290 K , a vessel (I) contains equal moles of three liquids (A, B, C). The boiling points of A, B and C…
At 290 K , a vessel (I) contains equal moles of three liquids (A, B, C). The boiling points of A, B and C are 350,373 and 308 K respectively. Vessel (I) is heated to 300 K and vapours were collected into vessel (II). Identify the correct statements. (Assume vessel (I) contains liquids and vapours and vessel (II) contains only vapours)
I. Vessel - I is rich in liquid $B$
II. Vessel - II is rich in vapour of C
III. The vapour pressures of A, B, C in Vessel (I) at 290 K follows the order $\mathrm{C}\gt\mathrm{A}\gt\mathrm{B}$.
I, II, III
I, II only
I, III only
II, III only
Solution
Boiling point $\propto \frac{1}{\text { vapour pressure }}$
Boiling point : $\mathrm{C} \lt \mathrm{A} \lt \mathrm{B}$
Vapour pressure : $\mathrm{B} \lt \mathrm{A} \lt \mathrm{C}$
I. Vapour pressure of B is lowest so it is in liquid phase.
II. Vapour pressure of C is highest so it is in the gaseous phase.
III. Order of vapour pressure : $\mathrm{C}\gt\mathrm{A}\gt\mathrm{B}$.
