V-L Quiz

What is the main condition for vapor-liquid equilibrium between two phases?

• Identical temperature only

• Identical pressure and concentration

• Departure from equilibrium proportional to mass transfer rate

• Phases must have the same volume

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

In a benzene-toluene mixture, as boiling continues, the mole fraction of benzene in the liquid phase (xA) moves:

• Toward zero

• To the right of the boiling point line

• Toward the bubble point line

• To the left since yA is richer in benzene

Which method of distillation involves the returning of a portion of the condensate to the still for contact with rising vapors?

• Flash distillation

• Steam distillation

• Batch distillation

• Fractional distillation with reflux

Relative volatility (α) between two components in a mixture is a measure of:

• The composition difference in the liquid phase only

• Separation difficulty based on vapor-liquid equilibrium

• The temperature of the system

• The energy required for separation

Which of the following statements is TRUE about flash distillation?

• It achieves high purity separations due to multiple stages.

• It is ideal for mixtures with closely boiling points.

• It involves single-stage vaporization and is suited for low-purity separation.

• It requires reflux to improve separation.

When conducting distillation with reflux, what term describes the ratio of the liquid returned to the column to the amount of distillate collected?

• Distillation efficiency

• Vapor-liquid equilibrium

• Enrichment factor

• Reflux ratio

Which of the following types of azeotropes exhibits a maximum boiling point?

• Ethanol-water system

• Benzene-toluene system

• Acetone-chloroform system

• Methanol-ethanol system

The McCabe-Thiele Method is primarily used to:

• Determine the equilibrium constant of a vapor-liquid system

• Calculate the energy requirements for flash distillation

• Estimate the number of theoretical stages in a distillation column

• Measure the relative volatility of non-ideal mixtures

In a distillation column, the section below the feed point is referred to as the:

• Enriching section

• Rectifying section

• Stripping section

• Refluxing section