Posted by Bob on .
A scuba diver's tank contains .25 kg of oxygen compressed into a volume of 4.3 L (for oxygen, 32g = 1 mole)
Calculate the gas pressure inside the tank at 9 degrees Celsius
What volume would this occupy at 26 degrees Celsius and .95 atmospheres?
can someone tell me how many moles i need and what other formula do i use?

chem 
DrBob222,
moles O2 = grams/molar mass.
Then PV = nRT, substitute and solve for P for the first part.
Use PV = nRT for the second part and solve for P.
I would use PV = nRT for the third part.