Question

How is ${O_3}$ estimated quantitatively?

Answer 1

Hint: We need to know what is ${O_3}$ and how it can be estimated quantitatively. Ozone, often known as trioxygen, is an inorganic molecule having the formula ${O_3}$. It's a light blue gas with a strong unpleasant odour. It is an oxygen allotrope that is significantly less stable than the diatomic allotrope ${O_2}$, decomposing in the lower atmosphere to ${O_2}$.

Complete answer:
We have to know that ozone may be measured quantitatively using potassium iodide. Iodine is released when ozone reacts with potassium iodide solution buffered with a borate buffer (pH 9.2). Using starch as an indicator, this released iodine may be titrated against a standard solution of sodium thiosulphate.
The equation for the reaction is as follows:
$2{I^ - }(aq) + {H_2}O(l) + {O_3}(g) \to 2O{H^ - }(aq) + {I_2}(s) + {O_2}(g)$
The liberated iodine is titrated against a standard solution of sodium thiosulphate and starch is used as an indicator. The reaction is as follows:
$2N{a_2}{S_2}{O_3} + {I_2} \to N{a_2}{S_4}{O_6} + 2NaI$
Sodium thiosulphate reacts with iodine to give sodium tetrathionate which is quantitatively estimated for ozone estimation.

Note:
It must be noted that the interplay of ultraviolet (UV) light and electrical discharges inside the Earth's atmosphere produces ozone from oxygen. It is found in extremely low quantities throughout the latter, with the maximum concentration high in the stratosphere's ozone layer, which absorbs the majority of the Sun's ultraviolet (UV) radiation.
Additional information: We have to know that ozone is one of the most potent oxidising agents known, considerably more potent than dioxygen. At large quantities, it is likewise unstable and degrades into conventional oxygen. Its half-life is affected by atmospheric variables including temperature, humidity, and air movement. Most metals (excluding gold, platinum, and iridium) will be oxidised by ozone to oxides of the metals in their maximum oxidation state. Ozone may be utilised in combustion reactions and combustible gases; ozone offers greater temperatures than dioxygen burning.