State Raoult's law for a solution containing volatile components. Write two characteristics of the solution which obeys Raoult's law at all concentrations.
Answer: p_A = x_A p°_A for each component. An ideal solution: ΔH_mix = 0 and ΔV_mix = 0 (A–B forces equal A–A and B–B).
Solution
Raoult's law: in a solution of volatile liquids, the partial vapour pressure of each component is directly proportional to its mole fraction:
A solution obeying this at every concentration is an ideal solution; its characteristics:
(i) — no heat is absorbed or evolved on mixing.
(ii) — the volume of the solution equals the sum of the volumes mixed.
(The A–B interactions are of the same strength as the A–A and B–B interactions.)
A solution obeying this at every concentration is an ideal solution; its characteristics:
(i) — no heat is absorbed or evolved on mixing.
(ii) — the volume of the solution equals the sum of the volumes mixed.
(The A–B interactions are of the same strength as the A–A and B–B interactions.)
CBSE Class 12 Board · 2016 · Subjective