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Liquefaction Of gasses and Isotherms?
The physical phenomenon by which a gas gets converted into a liquid state is termed as Liquefaction of gasses, and this process is also known as condensation. The liquefaction process is very complex, involving several contractions and expansions to attain elevated strains/pressures and significantly lower temperatures using an expansion turbine.
It is seen that the high-temperature isotherms are identical to an ideal gas. In contrast, underneath elevated strain/pressure, the gas cannot be converted into liquid. The curve indicates a variation from the ideal one when the gas temperature is lowered.
Till the temperature of 30.98 °C and 73 atm pressure, carbon dioxide is in a gaseous state. At pressure 73 atm and 30.98 °C, it is changed to liquid. This is called critical pressure, and this particular temperature is called critical temperature at a temperature beneath 30.98 °C. Conduct of the gas on additional pressure shifts in an alternate pattern. At 21.5 °C, simply up to point B as gas. At point B, some piece of CO2 becomes fluid, and some part becomes gas. With more fluid compression, the strain/pressure doesn’t change. Both fluid and vaporous types of carbon dioxide exist at point B. At point C, all the gas is condensed or liquefied. The gas compression changes volume from V2 to V3, which gives an increase in tension/pressure from P2 to P3. Even part of the isotherm displayed in the charts meets at the critical point. Points A and D address the vaporous and fluid states, and a moment under the vault shape addresses the fluid and solid forms in equilibrium. All the conduct shown by CO2 is valid for all gas.
Conditions Necessary for Liquefaction of gasses
Firstly the pressure should be high, and the temperature should be low.
Liquefaction and critical temperature(Tc)
Sir T. Andrews carried out the phenomenon of the Liquefaction of gasses in 1869, and he was successful in liquefying several of them. He found that regardless of how high the tension is applied, each gas has a temperature above which it can’t condense. This temperature is alluded to as the gas’ critical or primary temperature. It is possible to characterize it as follows:
The critical temperature of a substance/matter is the temperature above which the substance/matter cannot be converted to a liquid state of matter, despite any amount of pressure applied to that substance. In general, the metals have very high critical pressure and temperature values. The critical temperature of CO2 is 30.98 degrees C, and this means any amount of pressure applied to CO2 cannot liquefy it above 30.98 °C.
Tc is a symbol for the critical temperature. It is provided by- Tc=8a / 27bR
Where R is the gas constant and a and b are Van der Waal’s constants.
Critical pressure and critical volume:
Critical pressure and critical volume are the pressure applied and volume of gas at critical temperature respectively.
Pc=a / 27b2
Where a and b are Van der Waal’sWaal’s constant.
Vc is the symbol of Critical Volume symbol, and it is represented as Vc=3b
b is the effective volume of the molecules per mole of gas.
Pc , Vc and Tc are the critical gas constants.
Methods of Liquefaction Of gasses/ Air Liquefaction
Air is liquefied by using Linde’s method of Liquefaction of gasses and Claude’s method of Liquefaction of gasses.
There are two methods of Liquefaction of gasses.
Linde’s Process– The air is cooled, expanded and compressed in Linde’s process. Each expansion lowers the temperature considerably. At low temperatures, the atoms move all the more slowly and consume less space, so the air changes its state from gas to liquid. This is how air liquefaction takes place by Linde’s process.
Claude’s process– In Claude’s process, the gas is permitted to extend is entropically two times in two chambers. The gas is led through an expansion turbine in which it has to work while expanding. The gas isn’t yet fluid since that would annihilate the turbine. This is how air liquefaction takes place by Claude’s process.
Conclusion
Liquefaction Of gasses has vast significance. Thomas Andrews examined the natural connection between volume, temperature, and pressure in vaporous and liquid states of a matter/substance by studying the conduct of carbon dioxide.
For now, have a look at a few Frequently Asked Questions.
