1. The problem statement, all variables and given/known data The air in a room measuring 8 ft x 9 ft x 12 ft is at 80°F and 1 atm. Determine the mass of the air, in lb, and its weight, in lbf, if g = 32.0 ft/s2 2. Relevant equations 1 °F = 460.86°R dair = mair/vair 3. The attempt at a solution The air has the same mass as the room, thus mair = 8x9x12 mair = 864 ft3 dair = mair/vair dair = ρ/RT dair = 1 atm/(53.35 ft lb/lbm °R)(540.67°R) dair = 3.4668x10-5 atm lbm/ft lbf My density seems kinda low. What am I missing? Is it the gc?