Question

Please show ALL work. Conversions and formulas and everything there is.

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 14.5 × 18.5 × 9.0ft?

Express your answer using two significant figures.

Answer 1

Given :

Density of air = 1.19 g / L

Dimensions of room = (14.5 x 18.5 x 9.0 )ft³

Solution:

We have to find the mass of the air in kg. We use density , volume and mass relation.

Step 1 :

Calculation of volume of air in m^3 and then L

= (14.5 x 18.5 x 9.0 )ft³ x (1m³/ 35.31466 ft³)x 1000 L / 1m³)

= 68363.946 L

Step 2)

Calculation of mass by using density and volume.

Mass of air in g

= Density x volume

= 1.19 g L^-1 x 68363.946 L

= 81353.068 g

Calculation of mass of air in kg

= 81353.068 g x 1kg / 1000 g

= 81.35 kg

Ans in two sig fig is 81. Kg