At 35°C, the vapour pressure of `CS_(2)` is 512 mm Hg and of acetone is 344 mm Hg. A solution of `CS_(2)` and acetone in which the mole fraction of `CS_(2)` is 0.25, has a total vapour pressure of 600 mm Hg. Which of the following statement is correct ?

Options

A. A mixture of `100mL` of acetone and `100mL` of `CS_(2)` has a volume of `200mL`
B. When acetone and `CS_(2)` are mixed at `35^(@)C`, heat must be absorbed in order to produce a solution at `35^(@)C`
C. Process of mixing is exothermic
D. Entropy of mixing is zero

Explanation

`X_(A)P_(A)^(@)+X_(B)P_(B)^(@)=0.25xx512+0.75xx344=386mm`
Now `P_(A)+P_(B)=600 mm Hg` (Given)
so `P_(A)+P_(B)gtX_(A)P_(A)^(@)+X_(B)P_(B)^(@)`
therefore, there is positive devition from Raoult's law
`DeltaHgt0` i.e., heat is absorbed.