The phase diagram of carbon dioxide is below. It is a pretty typical phase diagram showing the temperature and pressure conditions under which CO2 can be a solid, liquid or gas. The bold lines show where two phases are in equilibrium. In the vapor phase molecules are far apart and this phase tends to be found at high temperature and low pressure conditions. The solid phase has molecules that are packed tightly together with strong intermolecular forces and therefore is found at high pressures and low temperatures. Pressure (atm) 5.2 Solid Liquid -78 -57 Temperature (C) Vapor Figure 1. Phase Diagram CO2 1. The triple point is the point at which all three phases are in equilibrium. Label the triple point on Figure 1.