CHLORINE

Used in water treatment

Very dilute

Cl₂  can react to form organochloride compounds (toxic)

Conditions- normal

                Cl_2(aq) + H₂O_(l) ↔ HClO + HCl

                Cl_2(aq) + H₂O_(l) ↔ 2H⁺ +ClO^- + Cl^-

Pale green due to the presence of Chlorine

Red when UI added due to chloric (1) acid but then bleaches

Used in swimming pools and disinfectants

Conditions- bright sunlight

                2Cl_2(aq) + 2H₂O_(l) → 4HCl + O₂

                2Cl_2(aq) + 2H₂O_(l) ↔ 4H⁺ + 4Cl^- + O₂

Conditions- with NaOH

Cold (15 c) dilute NaOH

                Cl_2(aq) + 2NaOH_(l) → NaCl + NaOCl + H₂O

Sodium chlorate (1)

Used in domestic bleach

Heated (above 70c)

3NaOCl → 2NaCl + NaClO₃

NaClO₃ is a powerful weed killer