chem
posted by mel .
a 13.5L tank is filled with H2 to a pressure of 2x10^2atm. How many balloons (each 2L) can be inflated to a pressure of 1 atm from the tank?assume there is no temp change and tank cant be emptied below 1 atm of pressure

PV = nRT will give you n = number of mols H2 in the tank originally.
Redo PV = nRT and substitute 1 for P and calcualte n = number of mols at the end (since P can't go below 1 atm).
Now use PV = nRT to calculate the mols used to fill a single balloon.
You should be able to determine how many balloons can be filled with the total mols you have.
Post your work if you get stuck.