20. Heat and Temperature

Solid water (ice) is slowly warmed from a very low temperature. (a) What minimum external pressure p1 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 p < p1.

(I) Water is in which phase when the pressure is 0.01 atm and the temperature is

(a) 90°C?

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

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

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