The triple point of CO₂ is at 5.2 atm and -57°C. Under atmospheric conditions present in a typical Boulder, Colorado, laboratory (P = 630 torr, T = 23° C), solid CO₂ will A) remain solid. B) melt. C) boil. D) sublime. E) none of these

Question

Quizplus · Accepted Answer

The triple point of a substance is the point where all three phases (solid, liquid, and gas) can coexist in equilibrium. At pressures and temperatures lower than the triple point, the substance cannot exist as a liquid or gas, only as a solid. Since the atmospheric conditions in the laboratory are below the triple point, CO₂ cannot exist as a liquid or gas and will sublime directly from solid to gas. Therefore, the answer is D, sublime.

The Triple Point of CO2 Is at 5

The Triple Point of CO₂ Is at 5