You are in browse mode. You must login to use MEMORY

level: LIQUEFACTION OF GASES

Questions and Answers List

level questions: LIQUEFACTION OF GASES

Question	Answer
Temperature above which liquid can no longer exist	• Critical Temperature (TC)
It is the pressure required to liquefy a gas at TC	• Critical Pressure (PC)
Methods of Achieving Liquefaction	• Subject to intense cold by the use of freezing mixtures • Adiabatic expansion • Joule-Thomson effect
Ideal gas to expand, done in vacuum or dewar flask where it uses its on energy content – drop of temperature can liquefy a gas	• Adiabatic expansion
Gas does external work	• Joule-Thomson effect
• Material that is liquid under the pressure conditions existing inside the container but that forms a gas under normal atmospheric conditions.	Aerosols
Vapor pressure of liquids	• When a liquid is placed in an evacuated container at a constant temperature, the molecules with the highest energies break away from the surface of the liquid and pass into the gaseous state, and some of the molecules subsequently return to the liquid state, or condense.
It is the relationship between the vapor pressure and the absolute temperature of a liquid is expressed by the	• Clausius-Clapeyron Equation
• Refers to the quantities of heat that are taken up when the liquids vaporize	Heat of Vaporization
The temperature at which the vapor pressure of the liquid equals to the pressure surrounding the liquid and the liquid changes into a vapor.	• Boiling point
SOLIDS characteristics	• Characterized as having fixed/definite shapes • Arranged in units • Nearly incompressible • Have strong intermolecular forces • Very little kinetic energy
What are the types of solid?	• Crystalline • Amorphous
Occurs by precipitation of the compound out of a solution into an ordered array	• Crystallization • Shows definite melting points
Variables that influence crystallization	• Solvents used • Temperature • Pressure • Crystalline array pattern • Purity of material • Salts
Have definite geometric forms with 6 common crystalline structures; what are these 6 common structures?	• Cubic • Tetragonal • Hexagonal • Rhombic • Monoclinic • Triclinic