Final answer:
The property of carbon dioxide that might have been under investigation is its melting point. The melting point of carbon dioxide is dependent on the pressure at which it is being measured.
Step-by-step explanation:
The property of carbon dioxide that might have been under investigation is its melting point.
Carbon dioxide exists in a solid form (dry ice), a gaseous form, and can also undergo sublimation, where it transitions directly from a solid to a gas without melting into a liquid. The investigation of its melting point would provide information about the conditions under which carbon dioxide transitions from a solid to a liquid state.
The phase diagram of carbon dioxide shows that its melting point increases with pressure, indicating that the melting point of carbon dioxide is dependent on the pressure at which it is being measured.