The density of air at ordinary atmospheric pressure and 25 ∘C is 1.19 g/L. What is the mass, in kilograms, of the air in a room that measures 12.5 * 19.5 * 6.0 ft?

Given:

The density of air = 1.19 g/L at 25°C and atmospheric pressure,

or

density = 1.19 x 10⁻³ kg/L

Volume of air in the room is

V = 12.5*19.5*6.0 = 1462.5 ft³

Note that

1 ft³ = 28.317 L

Therefore

V = (1462.5 ft³) * (28.317 L/ft³) = 4.1414 x 10 ⁴ L

By definition, mass = density*volume.

Therefore, the mass is

(1.19 x 10⁻³ kg/L) * (4.1414 x 10⁴ L) = 49.283 kg

Answer: 49.3 kg (nearest tenth)