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प्रश्न
Answer the following question based on the P-T phase diagram of carbon dioxide:
At what temperature and pressure can the solid, liquid and vapour phases of CO2 co-exist in equilibrium?
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उत्तर १
The P-T phase diagram for CO2 is shown in the following figure.

C is the triple point of the CO2 phase diagram. This means that at the temperature and pressure corresponding to this point (i.e., at –56.6°C and 5.11 atm), the solid, liquid, and vaporous phases of CO2 co-exist in equilibrium.
उत्तर २
At the triple point, temperature = – 56.6 °C and pressure = 5.11 atm.
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