Question

One of allotrope of oxygen is ozone. It is a pale-blue poisonous gas with strong odour.
A. True
B. False

Answer 1

Hint: There are many known allotropes of oxygen. One of the allotrope of oxygen is allotrope. Ozone is a highly toxic gas and acts as a sunblock for our earth. Chemical formula for ozone is $$O_3$$ . Ozone acts as a layer in the Stratosphere where Ozone concentration is high. Ozone is found in the stratosphere which is $10-50Km$ above the ground.

Complete step by step answer:
The upper Stratosphere consists of high concentration of ozone $$\left(O_3\right)$$, which protects our life and covers the whole planet from the harmful ultraviolet (UV) radiation coming from the sun towards the earth. Ozone $$\left(O_3\right)$$ is present in upper stratosphere and obtained as a byproduct of ultraviolet (UV) radiation acting on oxygen molecules $$\left(O_2\right)$$ .
Now first we will discuss the formation of ozone $$\left(O_3\right)$$. First step is that the UV radiation breaks molecular oxygen $$\left(O_2\right)$$ into free oxygen $$\left(O\right)$$ atoms. The first step can be written as follows:
$O_2(g)\stackrel{UV}{\to }O(g)+O(g)$
The next step is that oxygen $$\left(O\right)$$ atoms will combine with oxygen molecules $$\left(O_2\right)$$ to form ozone oxygen molecules $$\left(O_3\right)$$.
$$O(g)+O_2(g)\stackrel{UV}{\leftrightarrows }{O}_3(g)$$

When an ozone $$\left(O_3\right)$$ molecule absorbs UV radiation it breaks in a molecular oxygen $$\left(O_2\right)$$ and free oxygen $$\left(O\right)$$ atoms. The free oxygen $$\left(O\right)$$ atom obtained again combines with molecular oxygen $$\left(O_2\right)$$ to form ozone$$\left(O_3\right)$$. This cycle is called an ‘Oxygen-Ozone’ cycle and due to this cycle harmful ultraviolet (UV) radiations are continuously absorbed as heat.
Final Result: One of allotrope of oxygen is ozone. It is a pale-blue poisonous gas with strong odour.

So, the statement is true.

Note: The Ozone $$\left(O_3\right)$$ molecule absorbs ultraviolet (UV) rays between $310$ to $210$ nm wavelength. chlorofluorocarbon compounds (CFCs), nitrogen oxides, chlorine, tetrachloride are ozone depleting substances (ODS). More than $$1000ppm$$ of ozone leads to dizziness and headache.