How is `O_(3)` estimated quantitatively ?

Explanation

Quantitatively, ozone can be estimated with the help of potassium iodide. When ozone is made to react with potassium iodide solution buffered with a borate buffer (pH 9.2), iodine is liberated. This liberated iodine can be titrated against a standard solution of sodium thiosulphate using starch as an indicator. The reactions involved in the process are given below.
`underset("Iodide")(2I^(-)) + H_(2)O + underset("Ozone") (O_(3)) to 2 OH^(-)+ underset("Iodine")(I_(2)) + O_(2)`
`I_(2) + underset("thiosulphate")underset("Sodium") (2Na_(2) S_(2)O_(3)) to underset("trtrationate")underset("Sodium")(Na_(2)S_(4)O_(6)) + 2 NaI`