Dry ice, CO2(s), does not melt at atmospheric pressure. It sublimes at a temperature of −78 °C. What is the lowest pressure at which CO2(s) will melt to give CO2(l)? At approximately what temperature will this occur? (See Figure 10.34 for the phase diagram.)
Recall that using the phase diagram for CO2 from Figure 10.34, we can determine:
It is important to know that Dry ice, CO2 does not melt at atmospheric pressure but will sublime at −78 °C.