How will you prepare chlorine in the laboratory ?

Explanation

(i) Chlorine is prepared by the action of conc, sulphuric acid on chlorides in presence of manganese dioxide.
` 4NaCI + MnO_(2) + 4H_(2)SO_(4) to CI_(2) + MnCI_(2) + 4NaHSO_(4) + 2H_(2)O`
(ii) It can also be prepared by oxidising hydrochloric acid using various oxidising agents such as manganese dioxide, lead dioxide , potassium permangante or dichromate .
`PbO_(2) + 4HCI to PbCI_(2) + 2 H_(2)O + CI_(2)`
` MnO_(2) + 4HCI to MnCI_(2) + 2H_(2)O + CI_(2) `
` 2KMnO_(4) + 16HCIto 2 KCI + 2MnCI_(2) + 8 H_(2)O + 5CI_(2)`
` K_(2)Cr_(2)O_(7) + 14HCI to 2KCI + 2CrCI_(3) + 7H_(2)O + 3CI_(2)`
(iii) When bleaching powder is treated with mineral acids chlorine is liberated .
` CaOCI_(2) + 2HCI to CaCI_(2) + H_(2)O + CI_(2)`
` CaOCI_(2) + H_(2)SO_(4) + H_(2)O+ CI_(2)`