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:
${O_2}(g)\xrightarrow{{UV}}O(g) + O(g)$
The next step is that oxygen \[\left( O \right)\] atoms will combine with oxygen molecules \[\left( {{O_2}} \right)\] to form ozone oxygen molecules \[\left( {{O_3}} \right)\].
\[O(g) + {O_2}(g)\overset {UV} \leftrightarrows {O_3}(g)\]

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.