can anyone explain the isotherm of carbon dioxide?

1)The plot of pressure vs volume at different temperatures is called Isotherm.

 Thomas Andrew was first to study the phenomenon of effect of pressure on the volume of fixed volume of carbon  dioxide at different temperature

It was found that all real gases behave in the same manner as carbon dioxide.

2)A Gas can be liquefied  by increasing pressure and decreasing temperature.

3) Isotherm below is plotted by experimental measurements of volume of carbon dioxide at different pressure keeping the temperature constant each time.

4) At high temperature the curve is as that of ideal gas.

5)As temperature is lowered it shows deviation from ideal behavior .

6) When the temperature is lowered upto 30.98 ºC and at 73 atm pressure the gas gets liquefied .

7)30.98 ºC is known as the critical temperature and 73 atm pressure is known as critical pressure and the volume of gas at this point is known as critical volume . Above critical temperature gas can not be liquefied it remains in the vapour state.

8)At 13.1 ºC , on compression  Carbon dioxide remains a gas upto certain volume after that the pressure becomes contant i.e even on increasing compression , pressure does not change and thus at this point the liquid and gaseous carbon dioxide coexist.

9)On further increasing compression the gas condenses upto the point at which whole gas is liquefied and after this liquid carbon dioxide exists for which a steep slope is observed in the isotherm.

Below  30.98ºC  every temperature shows simmilar behavior .