Question

Isotherms of carbon dioxide at various temperatures are represented in Fig. 5.5. Answer the following questions based on this figure. 

(i) In which state will CO₂ exist between the points a and b at temperature T₁? 

(ii) At what point will CO₂ start liquefying when temperature is T₁? 

(iii) At what point will CO₂ be completely liquefied when temperature is T₂. 

(iv) Will condensation take place when the temperature is T₃. 

(v) What portion of the isotherm at T₁ represent liquid and gaseous CO₂ at equilibrium?

Answer 1

(i) At T₁ (between points ‘a’ and ‘b’) CO₂ exists in gaseous state.

(ii) At point b, CO₂ starts liquefying at T₁

(iii) At temperature T₁, at point ‘g’ CO₂ will be completely liquefied.

(iv) No condensation at T₃ since T₃ > T_C .

(iv) At T₁ liquid and gaseous CO₂ are at equilibrium between b and c.