Question

The density of air under ordinary conditions at 25°C is 1.19 g/L. How many kilograms of air is in a room that measures 11.0 ft x 12.0 ft and has a(n) 10.0 ft ceiling? 1 in =2.54 cm (exactly); 1 L = 10^3 cm^3?A. 45 x 10^4B. 0.1145C. 3.99D. 44.5E. 0.166

Answer 1

First, we define density as:

Density = mass/volume;

We focus first on the volume of air in the room.

Volume:

We have the measurements of where the air is.

We calculate the volume with these measurements, but first, we change the units to L:

1 inch = 2.54 cm

1 L = 10^3 cm^3

1 ft = 12 inch

Now,

11.0 ft x (12 in/1 ft) x (2.54 cm/1 in) = 335.28 cm

12.0 ft = 365.76 cm

10.0 ft = 304.8 cm

Therefore, the volume of the room = 335.28 cm x 365.76 cm x 304.8 cm

Volume = 37378237.5 cm^3 x (1 L/10^3cm^3) = 374 x 10^2 L

From the Density equation, we clear the mass:

Density x volume = mass (g)

1.19 g/L x 374x10^2 L = 445x10^2 g x (1 kg/1000 g) = 44.5 kg

Answer: 44.5 kg