Q. 11.22 Answer the following questions based on the P – T phase diagram of CO_{2} : 

(c) Describe qualitatively the changes in a given mass of solid CO_{2}  at 10\; atm pressure and temperature -65^{\circ}C as it is heated up to room temperature at constant pressure.

Answers (1)
S Sayak

At -65 oC under 10 atm pressure CO2 is in the solid phase. At room temperature (27 oC) under 10 atm pressure CO2 is in the vapour phase. At 10 atm pressure, CO2 can exist in all three phases depending upon the temperature. Therefore as CO2 is heated from -65 oC to room temperature at a constant pressure of 10 atm it goes from the solid phase to liquid phase and then ultimately it goes into the vapour phase.