5000 psi air weight density in 10 cubic feet?

5000psi is equal to the pressure at 11,545 ft of water. The density can be found from the equation lbs/ft^3=1.3 x inches-Mercury/Abs temp in Rankine.

This gives lbs/ft^3= 1.3 x 11545 x 1.13/460 =36.9 pounds ( the 1.13 is to convert inches mercury to ft water )

for 10 cuft that makes it 369 pounds.