Adding a Second Component to a Fixed-Volume Container

temperature (°C)

35

n-octane

n-hexane

add moles

n-octane

0

A container with a constant volume initially holds one component in the vapor phase (either

n

-octane or

n

-hexane). You can add the other component at constant temperature using a slider. A second slider changes the temperature. Select which is the second component with buttons. A pressure-composition (

P-x-y

) diagram for the mixture is shown on the left. The blue line is the bubble pressure and the orange curve is the dew-point pressure. The black dot corresponds to the overall composition and the pressure. If two phases are present, the

n

-hexane mole fractions of the liquid

x

1

(blue) and the vapor

y

1

(orange) phases are displayed. The bar graph on the right represents the number of moles of each component in the liquid and the vapor phase;

n

-hexane is in purple and

n

-octane is in green.