Under standard conditions, the density of oxygen is 1.429 g / L and that of air is 1.293 g / L Find (1) what is the mass fraction of oxygen in the air (2) mass ratio of oxygen to nitrogen in air (take integer ratio)

Under standard conditions, the density of oxygen is 1.429 g / L and that of air is 1.293 g / L Find (1) what is the mass fraction of oxygen in the air (2) mass ratio of oxygen to nitrogen in air (take integer ratio)

Let the volume of air be VL, then the volume of oxygen is 21% VL, mass of oxygen M = 21% VL * 1.429g/l = 0.3vg, mass of air = VL * 1.293g/l = 1.293vl (1) mass fraction of oxygen in air = 0.3vg/1.293vl * 100% = 23.2% (2) volume of nitrogen = 78% VL, mass of nitrogen = 78% VL * 1.25g/l = 0.975vg

Under standard conditions, when 6.2g Honglin is completely burned in air, what is the minimum volume of oxygen consumed? The oxygen density is 1.429g/l

It is known that the density of oxygen is 1.429g/l and that of air is 1.293g/l. The mass fraction of oxygen in air (density = mass / volume) is calculated

Let the volume of air be 1L, because the volume fraction of oxygen in air is 21%, so the volume of oxygen is 0.21l, the mass of air = 1L × 1.293g/l = 1.293g, the mass of oxygen = 0.21l × 1.429g/l = 0.3g, so the mass fraction of oxygen in air = 0.3g1.293g × 100% ≈ 23.2%