Question

At 90°C the vapour pressure of l,2·dimethylbenzene is 20kPa and that of 1,3-dimethylbenzene is 18 kPa.w'hat is the composition of the vapour of an equimolar mixture of the two components?

Answer 1

The composition of the vapor above an equimolar mixture of 1,2-dimethylbenzene and 1,3-dimethylbenzene is 52.6% 1,2-dimethylbenzene and 47.4% 1,3-dimethylbenzene.

Step-by-step explanation:

To determine the composition of the vapor of an equimolar mixture of 1,2-dimethylbenzene and 1,3-dimethylbenzene, we need to calculate the mole fraction of each component in the mixture.

The mole fraction of 1,2-dimethylbenzene is calculated by dividing its vapor pressure by the sum of the vapor pressures of both components. This can be expressed as X1 = P1 / (P1 + P2), where P1 is the vapor pressure of 1,2-dimethylbenzene and P2 is the vapor pressure of 1,3-dimethylbenzene.

Using the given values of the vapor pressures, we can calculate that X1 = 20 kPa / (20 kPa + 18 kPa) = 0.526. This means that the composition of the vapor above the equimolar mixture is 52.6% 1,2-dimethylbenzene and 47.4% 1,3-dimethylbenzene.