ANALYSIS OF ACID RADICALS
For systematic analysis of acid radicals, acid radicals can be divided into three groups.
1. Group-1 or Dilute acid group: This group includes the radical, which are decomposed by dilute acids. The group reagents of this group is dilute H2SO4 or dilute HCl. Following radicals belong to this group:
(i) CO32– (Carbonate)
(ii) HCO3– (Bicarbonates)
(iii) S2– (Sulphide)
(iv) SO32– (Sulphite)
(v) S2O32– (Thio-sulphate)
(vi) NO2– (Nitrite)
(vii) CH3COO– (Acetate)
(viii) CNS– (Thio-cyanate)
(ix) CIO– (Hypochloride)
2. Group-2 or Concentrated acid group: Radicals of this group are decomposed by concentrated acid and group reagent for radicals of this group is conc. H2SO4. Following radicals belong to this group:
(i) F– (Fluoride)
(ii) CI– (Chloride)
(iii) Br– (Bromide)
(iv) I– (Iodide)
(v) NO3– (Nitrate)
(vi) C2O42– (Oxalate)
(vii) C4H4O62– (Tartarate)
(viii) Other radicals are chlorate, permanganate, ferrocyanide, citrate etc.
3. Group-3 or Special group: Radicals of this group are identified by specific tests. Group includes following radicals:
(i) SO42– (Sulphate)
(ii) BO33– (Borate)
(iii) PO43– (Phosphate)
(iv) Other radicals are arsenate, arsenite, chromate, dichromate, silicate, iodate etc.
