Posted by pasely on .
Under water where the temperature is 17C and the pressure is 394 kPa, a diver inhales 2.1 L of air from his SCUBA tank.
a.How many moles of gas are in his lungs?
b.If the diver swims to the surface without exhaling where the temperature is 32C and the pressure changes to 100.2 kPa, what will the volume of the air in his lungs be?

Chemistry II 
DrBob222,
For a. Use PV = nRT. You know P and V, R and T. Solve for n.
For b, using n from part a, then use the new P and T to solve for V.
By the way, you can use kPa directly, if you wish, without changing to atmospheres IF you use 8.3145 for R.