Question

air is a mixture of N2 and O2 having 20% O2 by weight what is the density of air at STP
I will mark brainliest.... ​

Answer 1

Mass percent of O2 = 20

20g O2 in 100g air

1 mole of O2 = 32g = 22.4L

1g = 22.4/32 L

20g = 22.4 x 20 / 32 = 14L

Mass percent of N2 = 100 - 20 = 80

80g N2 in 100g air

1mol of N2 = 28g = 22.4L

1g = 22.4/28 L

80g = 22.4 x 80 / 28 = 64L

Total volume present of gases present in air = 14 + 64 = 78L

Density of air = Mass/Volume = 100/78 = 1.28 g/L