A 50.0 g piece of CO2(s) (i.e. “dry ice”) is sealed inside a 0.250 L container held at 20°C. Based on the phase diagram of CO2 (Figure 11.42 in the textbook), what state(s) of matter are present inside the container?

To answer this question, we need to refer to the phase diagram of CO2.

1. Identify the given conditions: We have a 50.0 g piece of CO2(s) (dry ice) sealed inside a 0.250 L container held at 20°C.

2. Convert the given temperature to Kelvin: 20°C = 293.15 K

3. Refer to the phase diagram of CO2: The phase diagram shows the state of matter of CO2 at different temperatures and pressures.

4. Locate the given conditions on the phase diagram: At 293.15 K, CO2 is in the gas phase under normal atmospheric pressure.

5. Determine the state of matter: Since the container is sealed, the pressure inside will increase as the dry ice sublimates. Depending on the exact pressure, CO2 could be in either the gas phase or the supercritical fluid phase.

6. Conclusion: Based on the given conditions and the phase diagram of CO2, the states of matter present inside the container could be gas and possibly supercritical fluid.