Anions (Carbonate & Sulfur Groups) PDF

Anions (carbonate & sulfur groups) presented by: Basma Hosam Anwar Assistant lecturer in Analytical chemistry department Analytical chemistry is classified into: Qualitative Quantitative Analysis Analysis Detection and Determinatio...

Anions (carbonate & sulfur groups) presented by: Basma Hosam Anwar Assistant lecturer in Analytical chemistry department Analytical chemistry is classified into: Qualitative Quantitative Analysis Analysis Detection and Determination of identification the concentration Qualitative Analysis (identification) Cations Anions (+ve charge) (-ve charge) Eg: NaCl Na+ Cl- Cation Anion  Process of identification 1) Dry 2) Wet 3) Special reaction reaction test Treatment of solid Treatment of salt Specific test samples to detect solution with for more the volatile reagents to give conformation products a color or ppt  Anions are classified into 6 groups: Group’s name Anion’s name Anion’s symbol and valency Carbonates Carbonate CO32 Sulfite SO32- Sulfur Thiosulfate S2O32- Sulfate SO42- Chloride Cl- Halides Bromide Br- Iodide I- Thiocyanate SCN- Cyanogens Ferrocyanide [Fe(CN)6]4- Ferricyanide [Fe(CN)6]3- Phosphate PO43- Phosphates and Arsenates Arsenate AsO43- Arsenite AsO33- Nitrogen Nitrite NO2- I) Carbonate group (CO3 ) -2 1) Dry reaction: pd + dil. HCl  strong effervescence + evolution of CO2 gas ( detected by turbidity of lime water Ca(OH)2) spatula dil. CO32- powder HCl Strong evolution of Lime CO32- effervescence CO2 gas water powder and evolution of Ca(OH)2 Step (1) Step (2) Step (3) CO2 gas Step (4) Turbidity of lime water by CO2 gas 2) Wet reaction: S.S + BaCl2 solution  white ppt 3) Special test: S.S + HgCl2  reddish brown ppt  II) Sulfur group (SO3 , S2O3 , SO4 ) -2 -2 -2  Name (SO3-2) Sulfite (S2O3-2) thiosulfate (SO4-2) Sulfate yellow colloidal ppt + A) Dry reaction: Weak eff. and evolution of Weak eff. and evolution of pd + dil. HCl SO2 gas, detected by SO2 gas which is detected -ve (prepare a paper decolorization of brown by decolorization of brown with I2 solution first) color of I2 paper color of I2 paper B) Wet reactions: White ppt White ppt 1) S.S + BaCl2 -ve (soluble in dil. HCl) (insoluble in dil. HCl) solution Purple color  upon 2) S.S+ FeCl3 solution Dark red color  brown ppt -ve standing colorless 3) S.S + I2 solution Decolorization of brown Decolorization of brown -ve (drop wise) color of I2 color of I2  Dry test of thiosulfate (S2O32-) Yellow colloidal ppt Decolorization of iodine paper  Lab precautions Lab tools THANK YOU