Question

47. Air is 21% oxygen by volume. Oxygen has a density
of 1.31 g/L. What is the volume, in liters, of a room
that holds enough air to contain 55 kg of oxygen?
(2) 1.3 x 106 L
(4) 2.0 x 105 L
(1) 5.5 * 105 L
(3) 2.7 x 106 L​

Answer 1

check your answer in image-:

Answer 2

Given:

Air is 21% oxygen by volume.

Oxygen has a density  of 1.31 g/L.

To Find:

Volume of room in litres that holds enough air to contain 55 kg of oxygen.

Solution:

Density =  $\frac{Mass}{Volume}$

It is given that, Room holds 55kg of oxygen i.e. 55000 g of oxygen.

Density =  $\frac{Mass}{Volume}$

=> 1.31 = 55000/V

=> V = 55000/1.31 = 41,984.73 L

Volume of oxygen in room is 41,984.73 L.

Now, Volume of oxygen is 21% of volume of air .

Let volume of air in room is x Litres.

=> 21% of x = 41984.73

=> $\frac{21}{100}$× x = 41984.73

=> x = 41984.73×100/21 = 199927.299 L ≈ 2×$10^{5}$ L

Also, Volume of room = Volume of air present in it

=> Volume of room = 2×$10^{5}$ L

Hence, Volume of room  is 2×$10^{5}$ L .