Answer the following questions based on the P-T phase diagram of carbon dioxide:

(a) At what temperature and pressure can the solid, liquid and vapour phases of \( CO_2\) co-exist in equilibrium?

(b) What is the effect of the decrease of pressure on the fusion and boiling point of \( CO_2\)?

(c) What are the critical temperature and pressure for \( CO_2\)? What is its significance?

(d) Is \( CO_2\) solid, liquid or gas at 

(a) –70°C under 1 atm, 

(b) –60°C under 10 atm, 

(c) 15°C under 56 atm?

Asked by Pragya Singh | 1 year ago |  216

1 Answer

Solution :-

(a) Liquid and vapour phases of CO2 co-exist at the triple point temperature 

= – 56.6°C and pressure = 5.11 atm.

(b) Both the boiling point and freezing point of CO2 decrease if pressure decreases.

(c) The critical temperature and pressure of CO2 are 31.1°C and 73.0 atm, respectively.

Above this temperature, CO2 will not liquefy even if compressed to high pressures.

(d) (a) vapour (b) solid (c) liquid

Answered by Pragya Singh | 1 year ago

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