20. Heat and Temperature

At atmospheric pressure, in what phases can CO₂ exist? Refer to Fig. 18 9 6.

Water is in which phase when the pressure is 0.01 atm and the temperature is 90°C?

Solid water (ice) is slowly warmed from a very low temperature. What minimum external pressure $p_1$ must be applied to the solid if a melting phase transition is to be observed? Describe the sequence of phase transitions that occur if the applied pressure $p$ is such that .

CO₂ exists in what phase when the pressure is 35 atm, and the temperature is 35°C (Fig. 18–6)?

For what range of pressures and temperatures can CO₂ be a liquid? Refer to Fig. 18-6.