[Sitkadiver]

OK, I need someone to verify that I am doing this correctly...

Accordingly to the gas laws PV = nRT, if I have a scuba tank that holds 108 cu. ft. of gas when pressurized to 2400 psi, then the same tank will hold 25% more gas when the pressure is increased to 3000 psi. Is that correct?

So, the 108 cu.ft. will become 135 cu. ft. if pressurized to 3000 psi..? Is that true?

[ebaines]

Accordingly to the gas laws PV = nRT, if I have a scuba tank that holds 108 cu. ft. of gas when pressurized to 2400 psi, then the same tank will hold 25% more gas when the pressure is increased to 3000 psi. Is that correct?

Yes - if you increase P while holding V and T constant, then n (the number of moles of gas in the tank) is increased. However, your base figure of the amount of gas is a bit confusing - the 108 cu ft figure is equivalent amount of volume of air at normal atmospheric pressure - about 15 psi. If you do the math, your tank must be 108 cu ft * 15 psi/2400 psi = 0.675 cu ft; does that sound right?

So, the 108 cu.ft. will become 135 cu. ft. if pressurized to 3000 psi..?? Is that true?

Yes - the amount of gas that occupies 135 cu ft at normal atmospheric pressure can be squeezed into the scuba tank if compressed to 3000 psi, just as 108 cu ft of gas at atmospheric pressure can be squeezed into that same volume at 2400 psi.