The number in Kg of oxygen that are present in the room is
403.1209 kg
calculation
mass=density x volume
density = 0.001429 g/ cm³
volume =775 cm x 1400 cm x 260 cm =2.821 x10^8 cm³
mass =0.001429 g/cm³ x( 2.8 x 10^8 cm³) =403120.9 grams
convert g to Kg
that is 1 kg = 1000 g
? kg =403120.9 g
by cross multiplication
=[(403120.9 g x 1 kg) /1000 g] =403.1209 kg
