Identification Tests

• Li+ + Na2CO3 → Li2CO3↓ + Na+ (White Precipitate Soluble in NH4Cl)
• Li+ + HCl → Crimson Flame
• Li+ + (SO4)2- → No Precipitate to distinguish it from Sr2+
• K+ + HCl → Violet/Lilac Flame
• K+ + NaHC4H406 → KHC4H406↓ + Na+ (White Precipitate soluble in NH4OH, NaOH, Na2CO3)
• Na+ + K2CO3 → No Precipitate to distinguish it from Li+
• Na+ + K2H2Sb2O7 → Na2H2Sb2O7↓+ K+ (White Precipitate)
• Ba2+ + HCl → Yellow-Green Flame
• Ba2+ + (SO4)2- → BaSO4↓ (Insoluble in HCl & HNO3)
• Ca2+ + (NH4)2C2O4 → CaC2O4↓ (Soluble in HCl but Insoluble in CH3COOH)
• Ca2+ + HCl → Yellow-Red Flame
• Mg2+ + (NH4)2CO3 → MgCO3↓+ 2NH4+ (White Hazy Precipitate)
• MgCO3 + Na2HPO4 → MgHPO4 ↓+ Na2CO3 (White Flocculant, insoluble in NH4OH)
• Al3+ + 3NH4OH → Al(OH)3↓ + 3NH4+ (White Gel Precipitate)
• Al(OH)3↓ + NH4OH → AlNH4(OH)4 (Precipitate dissolves at excess NH4OH)
• Al(OH)3↓ + NaOH → AlNa(OH)4 (Precipitate dissolves at excess NaOH
• 2Al3+ + 3Na2S + 6H2O → 2Al(OH)3↓ + 3H2S↑ + 6Na+ (Does not dissolve in excess OH-)
• B4O72- + H2SO4 + 5H2O → 4H3BO3 + SO42-
• H3BO3 + 3CH3OH → (CH3O)3B +3H2O (Green-Bordered Flame)
• SiO32- + NaPO3 → NaPO42- + SiO2 (Precipitate with Opaque Mass)
• CO32- + 2H+ → CO2↑ + H2O (Effervescence)
• CO2 + Ca(OH)2 → CaCO3↓ + H2O (White Precipitate)
• CO32- + phenolphthalein: pink (HCO3-, no color in Phenolphthalein)
• C2O42- + CaCl2 → CaC2O4↓ + 2Cl- (White Precipitate that is insoluble in Acetic Acid)
• Ca2C2O4↓ + 2HCl → CaCl2 + H2C2O4 (Precipitate dissolves at excess HCl)
• 5C2O42- + 2MnO4- + 16H+ → 10CO2↑ + 2Mn2+ + 8H2O (Decolorization of Permangenate, Effervescence of CO2)
• Pb2+ + H2SO4 → PbSO4↓ + H+ (White Precipitate difficult to distinguish from Barium Sulfate) (Insoluble in HNO3 and HCl) (Soluble in NaOH and weak acids)
• PbSO4↓ + 4NaOH → Na2Pb(OH)4 + Na2SO4 (Soluble)
• PbSO4↓ + 4CH3COONa → Na2Pb(CH3COO) 4 + Na2SO4 (Soluble)
• Pb2+ + Na 2CrO4 → PbCrO4↓ + 2Na (Yellow Precipitate insoluble in CH3COOH)
• PbCrO4↓ + 4NaOH → Na2Pb(OH)4 + Na2CrO4 (Soluble)
• NH4+ + 2NaOH → NH3↑ + 2Na + + H2O (Turns litmus paper to Blue) (Ammonia odor)
• 2NO3- + 6FeSO4 + 4H2SO4 → 3Fe2(SO4 )3 + SO42- + 4H2O + 2NO (Green FeSO4 turns into yellow/orang Fe2(SO4)3 due to the reaction with iron sulfate and sulfuric acid)
• [Fe(H2O)6]2+ + NO → [Fe(H2O)5(NO)]3+ + H2O (Brown Ring)
• NO3- + H2SO4 + Cu → CuSO4 + NO2 + H2O (NO2 Brown Gas)
• NO3- + KMnO4 → no discoloration (To differentiate it from NO2-)
• 5NO2- + 2KMnO4 + 3H2SO4 → 5NO3- + 2MnSO4 + K2SO4 + 3H2O (Discoloration of Permanganate)
• NO2- + H+ → HNO2 (Brown Fumes)
• 2HNO2 + 2KI + H+ → I2 + 2NO + 2H2O + 2K+ (Starch Iodine Blue Complex)
• HPO42- + 3AgNO3 → Ag3PO4↓ + 3NO3- + H+ (Yellow Precipitate)