Air was sampled through 37mm PVC membrane filter for seven hours and thirty seven minutes. The initial air flow rate was pre-calibrated twice at 49.7 and 50.1 secnds per liter.
What volume of air at STP (25 C and 760mm Hg) was sampled in liters?
same question in cubic feet?
volume= flowrate*time=1liter/49.9sec * time
figure time in seconds.