CHE553 Vapor Liquid Equilibrium

Phase diagram enables to view the properties of two or more phases as a function of temperature, pressure and other variables.

• TRUE

• FALSE

According to Raoult's Law, the partial pressure of a component in a vapor phase is directly proportional to

• Temperature

• Mole fraction of the component in the liquid phase

• System volume

• System pressure

Which of the following is INCORRECT.

• Bubble point calculation:

  Known P and x, calculate T and y

• Dew point calculation:

  Known x and y, calculate T and P

• Dew point calculation:

  Known T and y, calculate P and x

• Bubble point calculation:

  Known T and x, calculate P and y

• Activity coefficient accounts for non-idealities in the vapor phase

• Activity coefficient is a correction factor of Raoult's law for non-ideal solution

• Activity coefficient can be estimated by Margules, van Laar, Wilson and NRTL equation.

Henry's Law applies for species present as a very dilute solute in the liquid phase.

• TRUE

• FALSE

The composition of liquid and vapor is equal at azetrope.

• TRUE

• FALSE

Azeotrope exist when relative volatility at liquid composition (x₁ = 0 and x₁ = 1), one value is greater than 1 and the other value is less than 1.

• TRUE

• FALSE

When K_i is greater than 1, species i exhibits a higher concentration in the ______ phase.

• Liquid

• Vapor

A system is in two phase if the pressure is between bubble pressure and dew pressure.

• TRUE

• FALSE

P, T-flash calculation refers to any calculation of the ____________ of the vapor and liquid phases making up a two-phase system in equilibrium at known ____________.

• mole fraction

  T and P

• quantities and compositions

  T, P and z_i

• compositions

  T, P and xi

• mole fraction

  T, P and z_i