Calculate the volume of air required to obtain 39 liters of nitrogen if it is known that the volume fraction of nitrogen is 78%.

Given:

V (N2) = 39%,

Ɣ = 78%

V (air) -?

Decision:

Let’s take the air volume as 100 liters.

It is known that 78% of nitrogen is in the air.

This means that 100 liters of air contains 78 liters of nitrogen, and 39 liters of air contains x liters of nitrogen.

100 l (air) – 78 l,

x L – 39 L (N2).

x = (39 × 100): 78%,

x = 50 liters.

Answer: 50 liters.