In the stratosphere at an altitude of 20-30 km there is a layer of ozone O3, which protects the Earth from the powerful

In the stratosphere at an altitude of 20-30 km there is a layer of ozone O3, which protects the Earth from the powerful ultraviolet radiation of the Sun. If it were not for the “ozone screen” of the atmosphere, then high-energy photons would reach the surface of the Earth and destroy all life on it. It is estimated that, on average, there is 150 mol of ozone per inhabitant of a large city in the air space above the city. How many ozone molecules and what is its mass per citizen on average?

To solve this problem, we need:

m (mass of ozone molecule) – 48 (g)

Avogadro’s number is 6 x 10 ^ 23.

Well, then everything is simple.

1. Find the number of ozone molecules per one citizen of the planet Earth.

Let’s designate this quantity by the letter N. And we get.

N = 150 x 6 x 10 ^ 23 = 9 x 10 ^ 25 (molecules). And this falls on every citizen.

And in order to calculate the amount of ozone in grams per inhabitant of the city of planet Earth, we need to multiply the number of moles by the mass of one mole in grams.

Let us denote this quantity by the letter m. And then we’ll get it.

m = 150 x 16 x 3 = 7200 (grams) or 7.2 kg. (kilograms)