: Test for (CO3)-2 – 1 solid+dil.HCl→strong effervescent* *Soln.+BaCl2→white ppt soluble in HCl. 2 – Test for (SO4)-2 : *Soln.+BaCl2→white ppt. insoluble in HCl. 3 – Test for (Cl)-1 : *Soln. + lead acetate → white ppt (solid + distilled water)
Test for ammonia and coloured : cations .Cu ----- blue* .Fe+3 ----- reddish brown* .Cr+3 ----- dark green* .Co+2 ----- pink* .Ni+2 ----- green* :Test for ammonia (NH4)+1 – 1 solid+dil.NaOH→ammonia odour* : Test for Cupper (Cu)+2 – 2 *soln.+H2S → black ppt. *soln.+potassium ferrocyanide → chocolate brown ppt. 3 – Test for Cromium (Cr)+3 : *soln. + NH4Cl + NH4OH → greenish white ppt. : Test for Iron (Fe)+3 – 4 soln. + 3 drops conc.HNO3 →* boil → cool → NH4SCN → blood red color 5 – Test for Cobalt (Co)+2 : *solid+2 ml Amyl alcohol + 1gm NH4SCN → shake → blue colour in alcoholic layer. 6 – Test for Nickel (Ni)+2 : *soln.+NH4Cl+NH4OH (till ammonia odour appear)+Dimethyl glyoxime (D.M.G.)→red rose ppt. Solubility step
Solid + solvent → soluble*
Test for the six groups must be in order *Take part of solution then add reagent of gp 1 *If ppt → add gp reagent on all beaker then filter
Residue ppt of gp I
+2
Dissolve part of solid to form )(Clear Solution
*Sequence of solvents: *water (cold & hot). *Dil. HCl (cold & hot). *Conc. HCl (cold & hot).
*
Filterate gp II-VI
Group I : Pb+2, Hg2+2 ,Ag+ : *soln.+Cold dil. HCl → white ppt. *white ppt + 10 ml water, boil and filter → if *soluble → Pb+2 → if *insoluble → Hg2+2, Ag+ Confirmatory tests for lead pb+2 *soln.+KI → yellow ppt. *soln.+ K2CrO4 → yellow ppt. Confirmatory tests for Ag+ and Hg2+2 *Residue + dil NH4OH → if soluble → Ag+ insoluble → Hg2+2 :+)Confirmatory test For (Ag .Solution+ K2CrO4 → Red ppt* :Confirmatory tests for (Hg2)+2 Residue + aqua regia (3HCl:1HNO3)* in porcelain dish → evaporate till dryness → dissolve residue in few drops of water →add SnCl2 (stannous chloride) → white → grey → .black ppt Group II A (Pb+2, Hg+2, Bi+3, Cu+2, Cd+2). ).Group II B (As+3, Sb+3 , Sn+2 )
Adjustment of acidity (porcelain dish-1
.Soln. + methyl violet → bluish green*
.If
blue or violet → add HCl *
.green or yellow → add H2O :add group reagent –2 soln. (adjusted acidity) + excess H2S*
3-Test for complete precipitation *Filter → take part of filterate and then → add excess of H2S. *if→ppt→no complete precipitation so add excess of H2S. *If→No ppt→complete precipitation .
)Gp III (Al+3, Fe+3 and Cr+3
Precipitate Yellow ppt cd+2 or gp II B
Test for presence of H2S : *Paper moistened with lead acetate exposed to vapour of boiled solution → if black → boil again as H2S is still present.
Black or brown Bi+3, Cu+2, Hg+2 , Pb+2
If back or brown Small part of residue + 10 ml dil HNO3+10 ml dil H2SO4 → boil → *if → Soluble → Bi+3 or Cu+2 *if → Insoluble → Pb+2 or Hg+2 1 – confirmatory test for Bismuth (Bi)+3 *Soln+conc. NH4OH → white gelatinous ppt. 2 – confirmatory test for cupper (Cu)+2 : *Soln+conc.NH4OH → blue colour If insoluble → Pb+2 or Hg+2 *Part of residue+NH4AC → *if → soluble → Pb+2 → insoluble → Hg+2
Soln. + NH4Cl (solid) → dissolve →* .add dil NH4OH till amm. Odour if → white gelatinous ppt → Al+3 * reddish brown ppt → Fe+3
→
greenish white ppt → Cr+3
→
Part of residue+NaOH+H2O2 →* boil → if → soluble → Al+3 or Cr+3 insoluble → Fe+3
→
confirmatory test for (Al)+3-1 Part of solution + NH4Cl → boil* .→ cool → white ppt confirmatory test for (Cr)+3-2 *To yellow solution , add dil HAC+ 2 drops lead acetate → yellow ppt
*confirmatory tests as in group 1
*To differentiate between Cd and gpIIB : *To a part of yellow ppt → add 8% NaOH+1 drop of ammonium sulphide (H2O2)warm and shake → +2
*If → soluble → group II B → insoluble → Cd+2
Group II B Confirmatory tests for - 1 : Arsenic (As)+3 Soln. + Magnesium mixture (Mix* .of MgCl2 & NH4OH) → White ppt Confirmatory tests for - 2 : Stannous (Sn)+2 Soln + HgCl2 → white to grey to* .black ppt Filterate from gp II must be* .boiled to expel H2S
3-confirmatory test for (Fe)+3 *Part of residue + dil HCl → give clear solution. *Solution + NH4SCN → Blood red color. Group IV: Zn , Co and Ni *Soln. + NH4Cl (solid) → dissolve → add dil NH4OH till amm. Odour → add excess H2S. *if → white ppt → Zn+2 → black ppt → Co+2 or Ni+2 *Part of residue + 10 ml very dil HCl boil with stirring. *if → soluble → Zn+2 → insoluble → Co+2 or Ni+2 Confirmatory tests for Zinc-1 :(Zn)+2 Soln+acetic acid + potassium.* Ferrocyanide→greenish white ppt Confirmatory tests for Co+2 or -2 Ni+2 : *Residue + aqua regia → →evaporate to dryness → cool +2
+2
+2
add 5 ml water → boil → divide solution into two portions : *Tests for Co+2 & Ni+2 → As mentioned before. Group V: Ca+2, Ba+2 and Sr+2 *Boil filterate from gp IV to expel H2S and to concentrate the soln. *Conc. Soln.+ NH4Cl (solid) → dissolve → add Conc. NH4OH till amm. odour → add solid (NH4)2CO3 → white ppt. *Dissolve ppt in 10 ml dil. HAC and divided into 3 portions: Confirmatory tests must be done in the following sequence: 1-confirmatory Test for Ba+2: *Soln. + dil HAC+ K2CrO4 → yellow ppt. 2-confirmatory Test for Sr+2: *Soln. + (NH4)2SO4 → white +2 ppt 3-confirmatory Test for Ca : * Soln. + ammonium oxalate → white ppt. The filterate from gp V : is treated with ammonium sulphate + ammonium oxalate, heated to boiling. *After allowing standing for 5 minutes it is filtered and the residue is rejected and divide filterate 3 portions: Group VI: NH+4, Mg+2, Na+, K+ *Confirmatory tests must be done in the following sequence: 1-confirmatory Test for Mg+2 : *Soln+ NH4Cl (solid) → dissolve → add dil NH4OH + Na2HPO4 → scratching → white ppt. .
2-confirmatory Test for Na+ : *Soln + potassium pyroantimonate → white ppt. .
3-cofirmatory Test for K+ : *Soln. + dil HAC+ sodium cobalt nitrite → yellow ppt.