Today the grad students hosted a safety panel about different lab incidents that have happened in the past.
One of the stories we heard was about someone who almost asphyxiated in a walk in freezer due to dry ice.
Suffocating in a freezer, not a fun time.
Dry ice is frozen CO2, but the freezer was not cold enough to maintain a solid state. So, the dry ice slowly sublimated and gave off a ton of CO2 gas.
Combined with the fact the freezer is unventilated made for a scary situation.
But! The student recognized something was off immediately and left the freezer before anything bad happened.
How was he able to tell?
Many gases that cause asphyxiation are odorless and tasteless.
Nitrogen, argon, helium, and CO2.
So, situations where there is far less oxygen in the air than should be can be hard to detect until it is too late.
The grad student was able to tell something was wrong because the air felt heavier.
CO2 is heavier than oxygen.
In nature, oxygen is found as two oxygen atoms bound together.
So, the oxygen we breath is really dioxygen, O2.
Oxygen has a molar mass of 16g/mole.
Remember, a mole is 6.023×10^23.
So a molar mass is the mass you would have if you had one mole of it.
6.02×10^23 atoms of oxygen has a mass of 16.00 g/mole.
6.02×10^23 molecules of dioxygen has a mass of 32.00 g/mole.
But CO2 has an extra carbon, whose molar mass is 12.01 g/mole.
That means CO2 has a molar mass of 44.01 g/mole! Much heavier than O2!
And apparently, this is detectable when you breath it in.
Other gases like N2 (like oxygen, nitrogen is also diatomic in nature) and CO weigh less than O2. They are both 28.01 g/mole!
Unfortunately, I'm not sure if you can tell if it is lighter than oxygen.
So pay attention to your surroundings! You never know when that small feeling that something isn't right proves to be true!
#chemistry #everydayscience #science #scicomm #gas #carbondioxide #molarmass #oxygen #dryice - 2 hours ago