Question

Can carbon dioxide be liquefied at room temperature (20°C)? If so, how? If not, why not? (See the phase diagram in the preceding problem.)

a) Yes, by increasing pressure.

b) No, it requires extremely low temperatures.

c) Yes, by decreasing pressure.

d) No, it remains a gas at room temperature.

Answer 1

Carbon dioxide can be liquefied at room temperature (20°C) by increasing the pressure significantly above atmospheric levels, as indicated by the phase diagram of carbon dioxide.

Step-by-step explanation:

Carbon dioxide can indeed be liquefied at room temperature (20°C), but it requires increasing the pressure. According to the phase diagram for carbon dioxide, at atmospheric pressure (approximately 100 kPa), carbon dioxide is a gas at 20°C. However, by increasing the pressure significantly above atmospheric levels, you can induce the transition from the gaseous to the liquid state without changing the temperature.

For instance, at -30°C and 2000 kPa, carbon dioxide is in its liquid phase, and at -40°C and 1500 kPa, it remains liquid. At 20°C and standard atmospheric pressure, carbon dioxide is a gas, but the phase diagram indicates that applying higher pressure can alter its state to a liquid. Therefore, at room temperature, the transition from gas to a liquid would occur at a pressure much higher than the standard atmospheric pressure.