Give the preparation of chlorine.

Explanation

Preparation : Chlorine can be prepared by following methods:
i) Deacon.s process·: In this process, HCl gas get oxidised by atmospheric oxygen in the presence of `CuCl_2`
`4HCl+O_2overset(CuCl_2)to2Cl_2+2H_2O`
ii) Electrolytic process : Chlorine is prepared by electrolysis of concentrated NaCl solution.
`NaClrArrNa^(+)+Cl^(-)`
At cathode :`Na^(+)+ e^(-) to Na (s) `
At anode : `Cl^(-) to Cl + e^- , Cl + CltoCl_2 (g) `
Properties :
z) Chlorine reacts with metals and non-metals to form chlorides.
`2Na + Cl_2 to 2NaCl , 2Al + 3Cl_2 : 2AlCl_3`
`S_g + 4Cl_2 to 4S_2Cl_2`
ii) Chlorine reacts with excess of ammonia to form nitrogen and ammonium chloride.
`8NH_3+3Cl_2underset("(excess)")to6NH_4Cl+N_2`
iit)Chlorine in excess reacts with ammonia to form nitrogen trichloride (explosive).
`NH_3 + 3Cl_2 underset(("excess"))to NCl_3 + 3HCl`
(iv) Chlorine gives bleaching powder with dry slaked lime
`2Ca(OH)_2 + 2Cl_2 to underset("Cal. hypochloride")(Ca(OCl)_2 + CaCl_2) + 2H_2O`
The actural composition of bleaching powder is `Ca(OCl)_2, CaCl_2. Ca(OH)_2. 2H_2O`
`Ca(OH)_2 + Cl_2 to underset("Bleching powder")(CaOCl_2 + H_2O)`