Question

The vapour pressure of pure CHCl₃ and CH₂ Cl₂ are 200 and 41.5 atm respectively. The weight of CHCl₃ and CH₂ Cl₂ are resepectively 11.9 g and 17 g. The vapour pressure of solution will be

• A. 80.5
• B. 79.5
• C. 94.3
• D. 105.5

Answer 1

Answer: (C)

P⁰_CHCl3 = 200 atm $\quad\quad\quad$ P⁰_CH3Cl2 = 41.5 atm
n = $\frac{11.9}{119}$$\quad\quad\quad$ n = $\frac{17}{85}$
= .1 $\quad\quad\quad$ = .2
P_T = P⁰_AX_A+ P⁰_BX_B
$=200\times\frac{0.1}{.3}\quad\quad+\frac{41.5+0.2}{.3}$
$=94.33$