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Chemical Properties of Chlorine :

1) Reaction with dry SO: sulphuryl chloride is formed.

SO2 +Cl2 ——–> SO2Cl2 (sulphuryl chloride)

2) Reaction with carbon monoxide:

CO +Cl2 ———> COCl2 (carbonyl chloride)

3) Reaction with dry slaked lime Ca(OH):  We get bleaching powder

Ca(OH)2 +Cl2 ——>CaOCl2 (bleaching powder)  +H2O

4) Reaction with lime water : 

a) with cold lime water : calcium chloride  & Calcium hypo chlorite is formed.

2Ca(OH)2  +2Cl2  ——–> CaCl2 (calcium chloride) +Ca(OCl2)2 (Calcium hypo chlorite) +2H2O

b) with hot lime water : calcium chloride  & Calcium  chlorate is formed.

6Ca(OH)2 +6Cl2 ——–>  5CaCl2  +Ca(ClO3)2 ( calcium chlorate)+6H2O

5) Reaction with NaOH :

a) With cold and dilute NaOH :  Sodium  chloride  & sodium hypo chlorite is formed.

2NaOH +Cl2  ——–> NaCl  +NaClO (sodium hypo chlorite)+H2O

b) With hot and concentrated NaOH :   Sodium  chloride  & sodium  chlorate is formed.

NaOH +Cl2   ————> NaCl + NaClO3 (sodium chlorate) +H2O

6) Reaction with Ammonia :

a) With excess of NH3 : Nitrogen & ammonium chloride is formed .

2NH3 + 3Cl2  ——>N2  +6HCl

6HCl +6NH3 ——–> 6NH4Cl

Equation as a whole-

8NH3 + 3Cl2 ——-> N2 +6NH4Cl

b) With excess of Cl2 :  nitrogen tri-chloride is formed which is used as explosive.

NH3 + 3Cl2 ——–> NCl3 (nitrogen tri-chloride )(explosive) +3HCl

Oxidizing Properties:

It is presence of moisture chlorine acts as strong oxidizing agent.

a) It oxidizes H2S into S :

Cl2 +H2O ——–> 2HCl +O

H2S +O ——> H2O +S

Equation as a whole –

Cl2 + H2S    ——>2HCl + S

b) It oxidizes ferrous chloride into ferric chloride :

2FeCl2 +Cl2 ——-> 2FeCl3

c) It oxidizes acidic ferrous sulphate to ferric sulphate :

Cl2 +H2O ——->2HCl+ O

2FeSO4 + H2SO4 +O  —-> Fe2(SO4)3 + H2O

Equation as a whole –

2FeSO4 +H2SO4 +Cl2  —-> Fe2(SO4)3 +2HCl

d) It oxidizes  sodium  sulphite  to sodium sulphate :

Na2SO3 +Cl2 +H2O  ——>Na2SO4 +HCl

e) It oxidizes KBr into Br2 and KI into I2 :

2KBr +Cl2   ——> 2KCl +Br2

2KI + Cl2 ——> 2KCl +I2

Bleaching Properties:

In presence of moisture Cl2 acts as bleaching agent. Its bleaching action is due to its oxidizing properties. It bleaches colored flowers , leaves , wood pulp etc.

Cl2+ H2O ——–>2HCl + O (Nascent oxygen)

colored substance + O  ——-> colorless substance


Test of chlorine:

1. It bleaches colored flowers, leaves, wood pulp etc.

2. It turns starch iodide paper blue or violet. Starch- iodide paper contains  starch &  KI solution.

2KI +Cl2    ——–> 2KCl + I2.

I2 +starch ——-> blue color.

3. Aqueous solution of chlorine turns blue litmus red.

Uses :

  • It is used as oxidizing agent.
  • Chlorine acts as disinfectant and germicide.
  • As Bleaching agent.