To 300 liters of air was added 60 liters of nitrogen. Determine the volume fractions of oxygen

To 300 liters of air was added 60 liters of nitrogen. Determine the volume fractions of oxygen and nitrogen in the resulting mixture.

The generally accepted composition of air is a mixture of components containing 21% oxygen and 78% nitrogen by volume.

1. Let’s find how many liters of nitrogen and oxygen are:

V (N2) = V (air) * ϕ (N2 or O2) (in fractions);

V1 (N2) = 300 * 0.78 = 234 l;

V (O2) = 300 * 0.21 = 63 l;

2. After adding nitrogen, its total volume increases:

V2 (N2) = V1 (N2) + 60 = 234 + 60 = 294 l;

3. The volume of the gas mixture also increases:

V2 (gas mixture) = V (air) + 60 = 300 + 60 = 360 l;

4. Let’s calculate the volume fractions of gases in the new mixture:

ϕ2 (N2 or O2) = V (N2 or O2): V (mixtures);

ϕ2 (N2) = 294: 360 = 0.8167 or 81.67%;

ϕ2 (O2) = 63: 360 = 0.175 or 17.5%.

Answer: 81.67% N2; 17.5% O2.