36 Questions
What causes the drop in temperature during the Joule-Thomson effect?
Energy overcoming cohesive forces between molecules
What happens to the kinetic energy of gas molecules when the Joule-Thomson effect occurs?
It decreases
Which method for liquefying gases involves compressing air to about 200 atmospheres?
Claude’s method
In Claude's apparatus, where does a part of the air go after passing through pipe ABC?
Down the spiral towards a jet nozzle
What is required to cause liquefaction of a gas using methods based on the Joule-Thomson effect?
A sufficient drop in temperature
How does compression of air to about 200 atmospheres contribute to liquefaction in Claude's method?
It provides energy for cooling
What is the main purpose of liquefaction of gases?
To prepare pharmaceutical aerosols
Which method is responsible for the further cooling of precooled incoming compressed air in the liquefaction process?
Joule-Thomson expansion
How do the properties of liquids differ from those of gases in terms of compressibility and density?
Liquids are less compressible and have higher density than gases
What effect does the cooled air have on the portion of incoming compressed air in the liquefaction process?
It decreases the kinetic energy of gas molecules
Which factor plays a significant role in driving the engine during the liquefaction process?
Overcoming forces of attraction
In what state do liquids differ from gases in terms of molecule motion and volume assumption?
Gases have higher kinetic energy and fill all available space unlike liquids
What is the significance of critical temperature in relation to intermolecular forces?
Gases with high critical temperature have stronger intermolecular forces, making them easier to liquefy.
How does cooling a gas below its critical temperature affect the pressure required for liquefaction?
Decreases pressure required as cooling reduces intermolecular forces.
Which method is NOT commonly used to achieve gas liquefaction?
Boiling
What effect does compression have on gas molecules during liquefaction?
Compression brings molecules closer together, aiding in liquefaction.
What is the relationship between critical pressure and liquefaction of a gas?
Higher critical pressure makes liquefaction more difficult.
What role does intense coldness play in achieving gas liquefaction?
Intense coldness weakens intermolecular forces, aiding in liquefaction.
What does vapor pressure express for a molecule in a liquid?
Tendency to evaporate
Why do liquids with weak intermolecular forces have high vapor pressure?
Molecules escape readily
What does the Clausius-Clapeyron equation describe?
Vapor pressure and temperature relationship
Which factor affects the vapor pressure of a liquid at room temperature?
Nature of the liquid's intermolecular forces
How does the vapor pressure of a liquid change with increasing temperature?
Vapor pressure increases
Which type of liquids would you expect to have the highest vapor pressure at room temperature?
Liquids with weak attractive forces
What happens to the rate of condensation as the amount of vaporized liquid in the gaseous state continues to increase?
It increases until it equals the rate of vaporization
How do intermolecular forces in liquids compare to those in gases?
They are weaker in liquids
Which property of liquids explains their tendency to flow in response to external forces?
Viscosity
What effect does an increase in temperature have on the kinetic energy of the molecules of a liquid?
It significantly increases the kinetic energy
Which equation is used to describe the relationship between vapor pressure and temperature?
Clausius-Clapeyron Equation
What is the primary significance of the molar heat of vaporization in pharmaceutical applications?
Affecting drug stability
What happens to the vapor pressure of a liquid with a positive enthalpy of vaporization as temperature increases?
Increases exponentially
How does the addition of a non-volatile solute to a solvent affect the vapor pressure of the solution?
Decreases vapor pressure
Which equation is useful for understanding the interrelationship between vapor pressure and temperature of common liquids?
Clausius-Clapeyron equation
How does the boiling point of a liquid change in relation to the atmospheric pressure?
Boiling point increases as atmospheric pressure increases
What is the significance of the molar heat of vaporization (ΔHv) of a liquid?
It represents the heat absorbed during vaporization
Why do drugs with high vapor pressure have a tendency to diffuse out of tablets and vaporize?
Due to their low solubility in tablet matrices
Learn about the Joule-Thomson effect, which occurs when a gas expands adiabatically through a fine orifice, leading to a temperature drop. Explore how the energy expended in overcoming molecular forces results in this phenomenon.
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