An unknown substance kept in a sealed container at STP had a density of 808 kg/m3. When the container was opened and the substance was exposed to room temperature, its density became 1.25 kg/m3. Which change did the substance most likely undergo?

Question

An unknown substance kept in a sealed container at STP had a density of 808 kg/m3. When the container was opened and the substance was exposed to room temperature, its density became 1.25 kg/m3. Which change did the substance most likely undergo?
A. 
solid to liquid

B. 
liquid to solid

C. 
gas to liquid

D. 
liquid to gas

GPT-4o mini · Answer

The substance had a density of 808 kg/m³ when sealed in a container at standard temperature and pressure (STP). After being exposed to room temperature, its density changed to 1.25 kg/m³.

The significant decrease in density indicates that the substance transitioned to a less dense state, typical of gases. Specifically, the initial density of 808 kg/m³ suggests that the substance is likely a liquid or something denser than gas, but on exposure to room temperature, it becomes much less dense at 1.25 kg/m³, which aligns with that of a gas.

Based on this information, the most likely change the substance underwent is:

D. liquid to gas