Table Guide - Group I-V Cations PDF

EXPERIMENT #3 SUMMARY OF CATIONS GROUP (BASIC CONSTITUENTS) Groups I-IV are insoluble; Group V is soluble. Pb is present in Group I and II. Mercurous ions are in Group I; Mercuric ions are in Group II. CATIONS GROUP MEMBERS...

EXPERIMENT #3 SUMMARY OF CATIONS GROUP (BASIC CONSTITUENTS) Groups I-IV are insoluble; Group V is soluble. Pb is present in Group I and II. Mercurous ions are in Group I; Mercuric ions are in Group II. CATIONS GROUP MEMBERS RESULT & GROUP PRECIPITANT COLOR OF PPT 3M HCl Pb 2+ PbCl2 I. Insoluble Chlorides Hg2 2+ or Hg+ Hg2Cl2 Alternative: White (Silver (Mercurous ion) any soluble Group Cl- salt Ag+ AgCl (H-A-P) Example: Ag+ + HCl → AgCl (s) ↓ + H2 Adjust H+ to Cu Cu 2+ CuS Black 0.3 M and Subgroup: saturate with Na2S Bi 3+ Bi2S3 Brown- H2S (Source: insoluble Black Thioacetamid (C-B-C-P) Cd 2+ CdS Yellow e) Pb 2+ PbS Black II. Acid-Insolu Sn Subgroup: Sn 2+ SnS Brown ble Sulfides Na2S soluble (Hydrogen (S-A-S-H) Sn 4+ SnS2 Yellow Sulfide As 3+/5+ As2S3 and As2S5 Yellow Group) Sb 3+/5+ Sb2S3 Orange- red Hg 2+ HgS Black (mercuric) Red (if Cinnabar) Example: Cu + H2S → CuS (s) ↓ + H2 Transcribed by: Vince Resultay  CATIONS GROUP MEMBERS RESULT & GROUP PRECIPITANT COLOR OF PPT (NH4)2S Fe Subgroup: After addition Color of PPT or NaOH and of NaOH & Mixture of Na2O2 Na2O2 NH4Cl, NH3, insoluble (Sol. Agents) and H2S (Fe-Co-Ni-M n) Fe 2+/3+ FeS and Fe(OH)3 Fe2S3 Black III. Co 2+/3+ CoS Co(OH)3 Base-Insolu ble Sulfides Ni 2+ NiS Ni(OH)3 and Mn 2+ MnS MnO2 + H2O Flesh / Hydroxides (Hydrate of Salmon (Ammoniu Mn(OH)2) m Sulfide Group) Al Subgroup: Zn 2+ ZnS White NaOH and Na2O2 Al 3+ Al(OH)3 White Back to soluble gelatinous elemental form (Z-A-C) Cr 3+ Cr(OH)3 Grayish green Example: Cu + H2S → CuS (s) ↓ + H2 (NH4)2CO3, Alkaline Earth Metals: MgCO3 IV. Insoluble NH4Cl, NH3, Mg +2, Ca +2, Sr +2, Ba +2 CaCO3 White Carbonates and 95% SrCO3 (Alkaline ethanol (Mg-Ca-Sr-Ba) BaCO3 Earth Group) Example: (NH4)2CO3 + Mg → MgCO3 (s) ↓ + 2NH4Cl None Alkali Metals: Group V (cannot be Li+, Na+, K+ Cations precipitated; (Alkali / these are (Li-Na-K) None Soluble metals left in Group) the solution) Hypothetical Alkali metal: NH4+ Solubilizing Agents of Group II and II: Group II - Na2S (Sodium sulfide) Group III - NaOH (Sodium hydroxide) and Na2O2 (Sodium Peroxide) Transcribed by: Vince Resultay  1. Add 0.3 M HCl (Group 1 precipitant) to the solution. This will form the precipitate (s) of Group 1 cations. 2. After precipitation of Group 1, the centrifugate from Step 1 (in solution) contains the remaining cations of Group II-V. Adjust the pH (H+) to 0.3 M, then add H2S (Group 2 precipitant) to saturate the solution. This will form the precipitate (s) of Group 2 cations. 3. After precipitation of Group 2, the centrifugate from Step 2 (in solution) contains the remaining cations of Group III-V. Add the precipitant of Group 3 [(NH4)2S] and adjust the pH to basic (8). This will form the precipitate (s) of Group 3 cations. 4. After precipitation of Group 3, the centrifugate from Step 3 (in solution) contains the remaining cations of Group IV-V. Add the precipitant of Group 4 [(NH4)2CO3]. This will form the precipitate (s) of Group 4 cations. 5. Lastly, the centrifugate left from Step 3 (in solution) contains the remaining cations, which are the Group 5 cations. No more precipitant is added. Note: Precipitates are always in solid form, while centrifugate is in aqueous form (a mixture of remaining ions after centrifugation). Transcribed by: Vince Resultay  EXPERIMENT #4 GROUP I CATIONS - INSOLUBLE CHLORIDES GROUP IONS CONFIRMATORY TEST/S HCl NH4OH (group precipitant) Hg2Cl2 (a) boiling (b) excess NH4OH HgO.HgNH2N (a) excess White curdy water O3 & Hg0 ppt HgNH2Cl & Hg0 White and None None White and black black ppt (insoluble) (insoluble) ppt NaOH K2CrO4 Hg2O (a) excess Hg2CrO4 (a) NaOH Hg2 +2 Black ppt None Orange-red None (insoluble) ppt but (insoluble) brownish red on boiling KI Hg2I2 (a) excess Greenish-yellow or green ppt HgI4 -2 & Hg0; or K2HgI4 & Hg0 Colorless solution with black ppt HCl NH4OH (group precipitant) AgCl (a) boiling (b) excess NH4OH AgOH (a) excess White curdy water White ppt ppt to gray ppt Ag(NH3)2+ or Ag(NH3)2+ or when exposed None Ag(NH3)2Cl Ag(NH3)2OH to light (insoluble) Colorless solution Colorless solution Ag+ NaOH K2CrO4 AgOH to Ag2O (a) excess Ag2CrO4 (a) NaOH White to brown ppt None Brownish red None (insoluble) on boiling (insoluble) KI Transcribed by: Vince Resultay  AgI (a) excess Canary yellow ppt None (insoluble) HCl NH4OH (also the group precipitant) PbCl2 (a) boiling (b) excess NH4OH Pb(OH)2 (a) excess White crystal water None White ppt None ppt Colorless (insoluble) (insoluble) aqueous solution of PbCl2 (soluble) NaOH K2CrO4 Pb +2 Pb(OH)2 (a) excess PbCrO4 (a) NaOH White amorphous ppt Yellow ppt Pb(OH)4 -2 or Na2PbO2 Na2PbO2 Yellow Colorless solution solution KI PbI2 (a) excess Yellow ppt None (insoluble) GLOSSARY OF TERMS Hg0 - Elemental mercury Ag(NH3)2Cl - Diamine silver chloride Hg2I2 - Mercurous iodide AgOH - Silver hydroxide Hg2O - Mercurous oxide Ag2O - Silver oxide HgNH2Cl - Mercuric amido chloride Ag2CrO4 - Silver chromate HgO.HgNH2NO3 - Mercuric oxide and AgI - Silver iodide Mercuric amido nitrate PbCl2 - Plumbous / Lead (II) chloride Pb(OH)2 - Plumbous / Lead (II) hydroxide Hg2CrO4 - Mercuric chromate Pb(OH)4 -2 - Plumbic / Lead (IV) hydroxide HgI4 - Tetraiodomercurate Na2PbO2 - Sodium plumbite K2HgI4 - Potassium tetraiodomercurate PbCrO4 -Plumbous / Lead (II) chromate Ag(NH3)2 + - Silver diamine PbI2 - Plumbous / Lead (II) iodide Transcribed by: Vince Resultay  EXPERIMENT #5 GROUP II CATIONS - INSOLUBLE CHLORIDES GROUP IONS GENERAL TEST CONFIRMATORY TEST/S Copper Subgroup (C-B-C-P) H2S Na2S Reagent Color & Nature CuS Insoluble a) K4Fe(CN)6 Cu2Fe(CN)6 Black ppt Amorphous reddish brown ppt b) NH4OH Cu(OH)NO3 Cu +2 Green basic salt Excess NH4OH Cu(NH3)4 +2 or Cu(NH3)4(OH)2 Blue solution Bi2S3 Insoluble Na2SnO2 Bi 0 Dark brown ppt Black ppt Bi +3 or brownish black ppt CdS Insoluble K4Fe(CN)6 Cd2Fe(CN)6 Cd +2 Yellow ppt White ppt PbS Insoluble a) K2CrO4 PbCrO4 Black ppt Yellow ppt Pb +2 b) Excess NaOH Na2PbO2 or Pb(OH)4 -2 Yellow solution (soluble) Tin Subgroup (S-A-S-H) HgS Colorless a) SnCl2 Hg2Cl2 to Hg0 White to yellow solution of White to gray ppt to brown to Na2HgS2 black ppt b) KI HgI2 Hg +2 Scarlet red ppt c) Excess KI K2HgI4 or HgI4 -2 Colorless solution SnS Colorless HgCl2 Hg2Cl2 to Hg0 Sn +2 Light brown ppt solution of White to gray ppt Na2SnS3 Transcribed by: Vince Resultay  SnS2 Colorless a) Mg metal Reduction of Sn +4 to Sn +2 Yellow ppt solution of Colorless solution Sn +4 Na2SnS3 b) HgCl2 Hg2Cl2 to Hg0 White to gray ppt Sb2S3 Colorless a) Al metal Sb 0 Orange ppt or solution of Black ppt Sb +3 reddish orange Na3SbS4 ppt b) NaOBr None (insoluble) As2S3 Colorless NaOH, Al metal AsH3 & Ag 0 As +3 Yellow ppt solution of Colorless gas Na3AsS4 GLOSSARY OF TERMS CuS - Cuprous / Copper (II) sulfide PbCrO4 - Plumbous / Lead (II) chromate Cu2Fe(CN)6 - Cuprous / Copper (II) Na2PbO2 - Sodium plumbite ferrocyanide Pb(OH)4 -2 - Plumbic / Lead (IV) hydroxide Cu(OH)NO3 - Copper hydroxide nitrate Hg2Cl2 - Mercuric chloride Cu(NH3)4 +2 - Tetraammine copper (II) ion HgI2 - Mercuric iodide Cu(NH3)4(OH)2 - Tetraammine copper (II) HgI4 - Tetraiodomercurate hydroxide K2HgI4 - Potassium tetraiodomercurate Bi 0 - Elemental bismuth Sb 0 - Elemental antimony Cd2Fe(CN)6 - Cadmium ferrocyanide AsH3 - Arsenic trihydride / Arsine gas Transcribed by: Vince Resultay  EXPERIMENT #6 GROUP III CATIONS - AMMONIUM SULFIDE GROUP GENERAL TESTS NH4OH Excess NH4Cl & (NH4)2S NaOH Excess Na2O2 or IONS NH4OH NH4OH NaOH H2O2 Iron Subgroup (Fe-Co-Ni-Mn) Fe(OH)2 Insoluble Soluble FeS Fe(OH)2 Insoluble Fe(OH)3 White to Black ppt White to Reddish Fe +2 green to green to brown ppt brown ppt brown ppt Fe(OH)3 Insoluble Fe(OH)3 Fe2S3 Fe(OH)3 Insoluble No action Fe +3 Reddish Reddish Black ppt Reddish brown ppt brown ppt brown ppt Co(OH)NO3 Co(NH3)4 +2 Soluble CoS Co(OH)2 Insoluble Co(OH)3 Blue basic Dirty yellow Black ppt Blue ppt on Brown ppt Co +2 salt solution warming, or black pink ppt ppt Ni(OH)NO3 Ni(NH3)4 +2 Soluble NiS Ni(OH)2 Insoluble Ni(OH)3 Green basic Blue solution Black ppt Apple Green ppt salt green ppt with H2O2 Ni +2 No oxidation with Na2O2 Mn(OH)2 Insoluble Soluble MnS Mn(OH)2 Insoluble MnO2.H2O White to Flesh or White to Brown ppt Mn +2 light brown salmon ppt light brown ppt of ppt of MnO2.H2O MnO2.H2O Aluminum Subgroup (Z-A-C) IONS NH4OH Excess NH4Cl & (NH4)2S NaOH Excess Na2O2 or NH4OH NH4OH NaOH H2O2 Zn(OH)2 Zn(NH3)4 +2 Soluble ZnS Zn(OH)2 Na2ZnO2 No action White ppt Colorless White White ppt Colorless Zn +2 solution metallic solution ppt Transcribed by: Vince Resultay  Al(OH)3 Insoluble Al(OH)3 Al(OH)3 Al(OH)3 NaAlO2 No action White ppt White White White Colorless Al +3 gelatinous gelatinous gelatinous solution ppt ppt ppt Cr(OH)3 Insoluble Cr(OH)3 Cr(OH)3 Cr(OH)3 NaCrO2 Na2CrO4 Grayish Grayish Grayish Grayish Green Yellow Cr +3 green ppt green ppt green ppt green ppt solution solution (soluble) (soluble) CONFIRMATORY TESTS Iron Subgroup (Fe-Co-Ni-Mn) IONS REAGENTS FORMULA COLOR & NATURE KCNS None No reaction K4Fe(CN)6 Fe2Fe(CN)6 White to blue ppt Fe +2 Ferrous ferrocyanide K3Fe(CN)6 Fe3[Fe(CN)6]2 “Turnbull’s Blue” Ferrous ferricyanide Blue ppt KCNS Fe(SCN) +2 Blood red solution K4Fe(CN)6 Fe4[Fe(CN]6]3 “Prussian Blue” Fe +3 Ferric ferrocyanide Blue ppt K3Fe(CN)6 FeFe(CN)6 or Fe(CN)3 Brown solution Ferric ferricyanide Co +2 KNO2, HAc K3Co(NO2)6 Yellow ppt NH4OH, C4H7N2O2 C8H14O4N4Ni or Cherry red ppt Ni +2 (C4H7O2N2)2Ni Mn +2 HNO3, NaBiO3 HMnO4 Purple solution Aluminum Subgroup (Z-A-C) IONS REAGENTS FORMULA COLOR & NATURE K4Fe(CN)6 Zn2Fe(CN)6 or White ppt K2Zn3[Fe(CN)6]2 Zn +2 Rinmann’s Green Test: CoZnO2 Green ash Co(NO3)2, NH4OH Transcribed by: Vince Resultay  Aluminon Test: Al(OH)3 White gelatinous ppt to red lake NH4OH, Aluminon Al +3 Thenard’s Blue Test: Co(AlO2)2 Blue ash NH4OH, Co(NO3)2 NaOH, H2O2, or Na2O2 Na2CrO4 Yellow solution a) AgNO3 Ag2CrO4 Brownish red ppt Cr +3 b) BaCl2 BaCrO4 Yellow ppt c) Pb(CH3OO)2, HAc PbCrO4 Yellow ppt GLOSSARY OF TERMS Zn(NH3)4 +2 - Tetraamminezinc Na2ZnO2 -Sodium zincate ZnS -Zinc sulfide Co(AlO2)2 - Cobalt metaluminate Co(OH)NO3 - Cobalt hydroxide HMnO4 -Permanganic acid nitrate Fe4[Fe(CN)6]3 - Ferric ferrocyanide / Prussian Blue Ni(OH)NO3 -Nickel hydroxide FeFe(CN)6 - Ferric ferricyanide nitrate Fe2Fe(CN)6 - Ferrous ferrocyanide Ni(NH3)4 +2 - Fe3[Fe(CN)6]2 - Ferrous ferricyanide / Turnbull’s Blue Tetraamminenickel K3Co(NO2)6 - Potassium hexanitritocobaltate(III) NaAlO2 - Sodium aluminate C8H14O4N4Ni - Nickel bis(dimethylglyoximate) Na2CrO4 -Sodium chromate GUIDE FOR NAMING IRON + FERRO- / FERRICYANIDE COMPOUNDS Transcribed by: Vince Resultay  EXPERIMENT #7 GROUP IV CATIONS - ALKALINE EARTH GROUP IONS Ba +2 Sr +2 Ca +2 Mg +2 Yellowish Green Crimson / carmine Brick / dull red Colorless / bright FLAME TEST red white BaCO3 SrCO3 CaCO3 Absence of White ppt White ppt White ppt alcohol: MgCO3.Mg(OH)2 1. (NH4)2CO3, NH4Cl, NH4OH, Presence of C2H5OH alcohol: MgCO3. (NH4)2CO3.4H2O BaCrO4 SrCrO4 CaCrO4 Soluble Yellow ppt Yellow ppt Yellow ppt, can 2. K2CrO4 dissolve in the presence of alcohol 2.1. CH3COOH Insoluble Soluble Insoluble BaC2O4 SrC2O4 CaC2O4 Soluble 3. K2C2O4 White ppt White ppt White ppt 3.1. CH3COOH Soluble Soluble Insoluble BaSO4 SrSO4 CaSO4 Very soluble White ppt White ppt White ppt, can 4. (NH4)2SO4 dissolve in the presence of alcohol Insoluble Soluble (in boiling Soluble 4.1. HCl HCl) Ba3(PO4)2 Sr3(PO4)2 Ca3(PO4)2 MgNH4PO4 5. Na2HPO4, White amorphous White amorphous White amorphous White crystalline NH4OH ppt ppt ppt ppt Transcribed by: Vince Resultay  EXPERIMENT #8 GROUP V CATIONS - ALKALI GROUP REAGENTS FORMULA COLOR & NATURE FLAME TEST IONS OF PRODUCTS KH2SbO4 or NaH2SbO4 or White crystalline K2H2Sb2O7 Na2H2Sb2O7 ppt Intense Yellow / Na+ Golden Yellow Zinc / cobalt uranyl NaZn(UO2)3(CH3COO)9. Yellow crystalline acetate 6H2O ppt Yellow crystalline Na3Co(NO2)6 K2NaCo(NO2)6 ppt K+ Violet White crystalline H2C4H4O6 KHC4H4O6 ppt Na2HPO4, NH4OH Li3PO4 White ppt a) HCl Crimson and Li+ (acid-soluble) carmine red Soluble b) NH4OH (base-soluble) K2HgI4 (alkaline) HgO.HgNH2I Orange ppt NH4+ Increase in NH3 + H2O = ammoniacal odor Colorless NaOH, heat (urine odor) Red litmus paper Red to blue litmus paper GLOSSARY OF TERMS KH2SbO4 - Potassium biantimonate K2H2Sb2O7 - Pyroantimonate NaH2SbO4 - Sodium dihydrogen antimonate H2C4H4O6 - Tartaric Acid KHC4H4O6 - Sodium bitartrate K2NaCo(NO2)6 - Dipotassium sodium cobaltinitrite HgO.Hg(NH2)I - Mercuric amidoiodide / Iodide of Million’s Base Transcribed by: Vince Resultay  Cation Group Number Group Name I Chlorides, insoluble group / Silver Group II Acid-insoluble group / Acid Hydrogen Sulfide Group III Base-insoluble group / Ammonium Sulfide Group IV Carbonate-insoluble group / Alkaline Earth Group V Soluble group / Alkali Group Transcribed by: Vince Resultay