The vapour pressure of n-hexane at 350 K is 840 torr and that of cyclohexane is 600 torr. Mole fraction of hexane in the mixture that boils at 350 K and 1 atm pressure assuming ideal behaviour is

Question

The vapour pressure of n-hexane at 350 K is 840 torr and that of cyclohexane is 600 torr. Mole fraction of hexane in the mixture that boils at 350 K and 1 atm pressure assuming ideal behaviour is (A) 0.67 (B) 0.80 (C) 0.50 (D) 2.2

Tardigrade Admin · Accepted Answer

Mixture boils at 1 atm and 350 K Thus, total vapour pressure is 1 atm = 760 torr (h) used for hexane and (ch) for cyclohexane P texttotal=Pho chiho+Pcho chich ⇒ P texttotal =Pho chih+Pcho(1- chih) 760=840 chih+600(1- chih) ∴ chih=0.67

Q. The vapour pressure of $n$ -hexane at $350 K$ is $840$ torr and that of cyclohexane is $600$ torr. Mole fraction of hexane in the mixture that boils at $350 K$ and $1$ atm pressure assuming ideal behaviour is

$0.67$

$0.80$

$0.50$

$2.2$

Q. The vapour pressure of n-hexane at 350K is 840 torr and that of cyclohexane is 600 torr. Mole fraction of hexane in the mixture that boils at 350K and 1 atm pressure assuming ideal behaviour is

0.67

0.80

0.50

2.2

Mixture boils at 1 atm and 350K Thus, total vapour pressure is 1 atm = 760 torr (h) used for hexane and (ch) for cyclohexane Ptotal​=Pho​χho​+Pcho​χch​ ⇒Ptotal​=Pho​χh​+Pcho​(1−χh​) 760=840χh​​+600(1−χh​) ∴χh​=0.67

Q. The vapour pressure of $n$ -hexane at $350 K$ is $840$ torr and that of cyclohexane is $600$ torr. Mole fraction of hexane in the mixture that boils at $350 K$ and $1$ atm pressure assuming ideal behaviour is

$0.67$

$0.80$

$0.50$

$2.2$