Uses of fluorine:

(i) It is used in the preparation of fluoro carbon which are non-inflammable and chemically inert and are used as solvents, lubricants and insulator.
(ii) It is used as a refrigerant in many of the cooling processes.
(iii) It finds considerable use as DDFT, which similar to DDT, is extremely; efficient as a fungicide and fumigant.
(iv) In nuclear physics and higher voltage electricity, fluorine as SF₆ finds very great use e.g., in the separation of isotopes of uranium.


Uses of chlorine:

(i) It is used in sterilization of drinking water.
(ii) Large quantities of chlorine are used for bleaching paper pulp and textiles.
(iii) It is used in the manufacture of inorganic chemicals such HCl, sodium hypochlorite (NaOCl), bleaching powder (CaOCl₂), phosphorus trichloride (PCl₃) phosphorus pentachloride (PCl₅) etc.
(iv) It is used in the manufacture of vinyl chloride which is the starting material for the plastic polyvinyl chloride (PVC).
(v) It is used in the manufacture of insecticides like DDT, germicides, dyes and drugs.