Gas Mixtures and Vapor Pressure Concepts

This video tutorial explains various types of pressure, including atmospheric, gauge, absolute, manometric, vapor, and partial pressure. It clarifies common misconceptions and provides guidance on when to use each type in chemical engineering calculations. The tutorial also covers the measurement of these pressures and their dependence on factors like temperature and gas mixtures.

What is the primary factor that causes atmospheric pressure to fluctuate?

• Weight of the air column

• Humidity levels

• Wind speed

• Temperature changes

How does a gauge pressure reading differ from an absolute pressure reading?

• Gauge pressure is measured in PSI, while absolute pressure is measured in bars.

• Gauge pressure includes atmospheric pressure, while absolute pressure does not.

• Gauge pressure is always higher than absolute pressure.

• Gauge pressure is relative to atmospheric pressure, while absolute pressure includes it.

What device is commonly used to measure manometric pressure?

• Manometer

• Thermometer

• Barometer

• Hygrometer

Which factor does vapor pressure depend on?

• Atmospheric pressure

• Amount of liquid

• Temperature

• Volume of the container

In a phase diagram, what does the red line between liquid and vapor phases represent?

• Melting point

• Freezing point

• Sublimation point

• Boiling point

What is the partial pressure of a gas in a mixture?

• The pressure it exerts at sea level

• The pressure it would exert if it occupied the entire volume alone

• The pressure it exerts when mixed with other gases

• The pressure it exerts at absolute zero

How is the total pressure of a gas mixture determined?

• By adding the partial pressures of all components

• By multiplying the partial pressures of all components

• By subtracting the lowest partial pressure from the highest

• By adding the vapor pressures of all components

Under what condition can vapor pressure and partial pressure be equal?

• When the atmospheric pressure is high

• When the gas is at its boiling point

• When the temperature is constant

• When a pure liquid is in equilibrium with its vapor

What happens to the partial pressure of water vapor as it evaporates into dry air?

• It fluctuates randomly

• It remains constant

• It increases

• It decreases

Why can the partial pressure never exceed the vapor pressure?

• Because it would lead to condensation

• Because equilibrium would be disrupted

• Because it would cause the liquid to freeze

• Because vapor pressure is always higher