TPRH science workbook Chem problem

[podyon18]

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Q: One of the limitations of using a gas as a shock absorbing cushion is that under high pressure, the gas may liquefy and lose compressibility. Which of the following gases would be the best one to use in light of this concern?

A. CO2, B. Water vapor, C. Bromine gas, D. Ammonia gas.


The correct answer was A as it had the lowest boiling point and the answer key just states that we want to pick the gas with the lowest condentation/boiling point without explaining why.


I am confused. Can someone please explain why lower BP is better in this context?

 

[Dasypus]

I know this is really qualitative and hand-wavey, but: the lower the boiling point, the 'more gassy' the gas is at room temperature; it's got more wiggle room in the gas part of its phase diagram. More room there, more space for added pressure without making the phase transition.

 

[MedPR]

This is how I thought of it.

Lowest BP = highest VP = harder to compress.

 

[chiddler]

"the gas may liquefy and lose compressibility".

so look for the gas that does not liquify and lose compressibility. CO2 is best answer since it has least amount of intermolecular forces as a gas.

 

[kasho11]

I thought of it as which is more likely to become a liquid. Bromine and ammonia gas are easily converted into liquids. Water vapor, well, obviously. So CO2 was left.