Question

Estimate the fraction of molecular volume to the actual volume occupied by oxygen gas at STP. Take the diameter of an oxygen molecule to be 3Å.

Answer 1

Diameter of O2 molecule = 3A°
So, radius of O2 ( r) = 1.5A°
So, volume of one O2 molecule = 4/3 πr³
= 4/3 × 22/7 × 1.5 A°³

In one mole = 6.023 × 10²³ molecule ,

So, volume of one mole of O2 molecules ( actual volume ) = 4/3 × 21/7 × 1.5 × 10^-30 × 6.023 × 10²³ = 8.51 × 10^-6 m³
= 8.51 × 10^-3 L

We know,
the volume of one mole of a gas at STP
= 22.4 L

So, fraction of molecular volume to actual volume = 8.51 × 10^-3/22.4
= 3.8 × 10^-4

Answer 2

this is the answer, thanks you