A solution has a 1 : 4 mole ratio of pentane to hexane. The vapour pressure of the pure hydrocarbons at 20°C are 440 mm of Hg for pentane and 120 mm of Hg for hexane. The mole fraction of pentane in the vapour phase would be :

Question

Dr. Abubacker · Accepted Answer

[Solution from source] x(pentane) = 1/5 = 0.2. p(pentane) = 0.2 × 440 = 88 mm and p(hexane) = 0.8 × 120 = 96 mm, total 184 mm. Vapour mole fraction of pentane = 88/184 ≈ 0.478. Answer (4).

Q. A solution has a 1 : 4 mole ratio of pentane to hexane. The vapour pressure of the pure hydrocarbons at 20°C are 440 mm of Hg for pentane and 120 mm of Hg for hexane. The mole fraction of pentane in the vapour phase would be :

Explanation

Reviewed by Dr. Abubacker

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