Full Salt Analysis Cheatsheet

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I. Preliminary Tests Experiment Observation Inference 1. Colour and Appearance Colourless Absence of $Cu^{2+}$, $Fe^{2+}$, $Ni^{2+}$, $Co^{2+}$ salts. 2. Solubility i) In $H_2O$ Soluble Presence of water soluble salts. ii) In dil HCl Insoluble (Exp 1) Soluble (Exp 2, 3, 4, 5, 6, 7, 8, 9, 10) Presence of Group I radical (Exp 1) Absence of Group I radical (Exp 2, 3, 4, 5, 6, 7, 8, 9, 10) 3. Smell Take a pinch of salt, rub with water. No Characteristic smell (Exp 1, 2, 5, 6, 8, 9, 10) Brisk effervescence (Exp 3) Presence of Ammoniacal smell (Exp 4, 7) Absence of $(NH_4^+, CH_3COO^-)$ (Exp 1, 2, 5, 6, 8, 9, 10) May be presence of Carbonates (Exp 3) May be presence of $NH_4^+$ (Exp 4, 7) 4. Dry Heating Small amount of salt heated in dry test tube. Reddish brown gas evolved (Exp 1, 5, 6) No Characteristic change observed (Exp 2) Reddish brown gas with pungent smell turns $FeSO_4$ solution black (Exp 1, 5, 6) May be presence of $NO_3^-$ (Exp 1, 5, 6) Absence of $NO_3^-$ (Exp 2) 5. Zero Group Test Salt + NaOH, heat. Glass rod dipped in conc. HCl near mouth. No Characteristic change observed (Exp 1, 2, 5, 6, 8, 9, 10) Presence of Ammoniacal smell with white dense fumes (Exp 4, 7) Indicates absence of $NH_4^+$ (Exp 1, 2, 5, 6, 8, 9, 10) May be presence of $NH_4^+$ (Exp 4, 7) 6. Flame Test Salt paste with conc. HCl into non-luminous flame. Dull bluish white flame (Exp 1) No Characteristic change observed (Exp 2, 4, 7, 8, 9, 10) Crimson red flame (Exp 5) Green Colour flame (Exp 6) May be presence of $Pb^{2+}$ (Exp 1) Indicates absence of $Ca^{2+}, Sr^{2+}, Ba^{2+}, Cu^{2+}, Zn^{2+}, Mn^{2+}, Pb^{2+}$ (Exp 2, 4, 7, 8, 9, 10) May be presence of $Sr^{2+}$ (Exp 5) May be presence of $Ba^{2+}$ (Exp 6) 7. Ash Test Salt + Cobalt Nitrate solution, heat in flame. No Characteristic ash observed (Exp 1, 2, 4, 5, 6, 7, 8, 9, 10) Blue ash observed (Exp 3) Absence of $Al^{3+}, Zn^{2+}, Mg^{2+}$ (Exp 1, 2, 4, 5, 6, 7, 8, 9, 10) May be presence of Aluminium (Exp 3) 8. Dilute $H_2SO_4$ Test Salt + dil $H_2SO_4$. No Characteristic change observed (Exp 2, 4, 5, 6, 7, 8, 9, 10) Colourless, Odourless gas with brisk effervescence, lime water turns milky (Exp 3) Indicates absence of $CO_3^{2-}$ (Exp 2, 4, 5, 6, 7, 8, 9, 10) May be presence of $CO_3^{2-}$ (Exp 3) 9. Conc. $H_2SO_4$ Test Salt + conc. $H_2SO_4$, warm. Reddish brown gas with pungent smell turns $FeSO_4$ solution black (Exp 1, 5, 6) Reddish brown gas (Exp 2) Colourless gas with pungent smell (Exp 4, 8, 9, 10) Indicates presence of $NO_3^-$ (Exp 1, 2, 5, 6) Indicates absence of $Cl^-, Br^-, NO_3^-$ (Exp 4) May be presence of $Cl^-$ (Exp 8, 9, 10) II. Wet Tests Preparation of Original Salt Solution (O.S.S) The given salt is soluble in water. Water extract is prepared. Acidic Radical Confirmatory Tests 1. Nitrate ($NO_3^-$) Copper Chip Test: Experiment: O.S.S + conc. $H_2SO_4$ + copper chips, heat. Observation: Light brown fumes observed, intensifying on heating. Inference: Confirms presence of Nitrate Radical. Brown Ring Test: Experiment: O.S.S + freshly prepared $FeSO_4$ solution + conc. $H_2SO_4$ slowly along test tube sides. Observation: A dark brown ring obtained at the interface. Inference: Confirms presence of Nitrate Radical. 2. Carbonate ($CO_3^{2-}$) $MgSO_4$ Test: Experiment: O.S.S + few drops of $MgSO_4$. Observation: White precipitate is formed. Inference: Confirms presence of Carbonate. 3. Sulphate ($SO_4^{2-}$) Lead Acetate Test: Experiment: O.S.S + few drops of Acetic acid + lead acetate. Observation: White precipitate of $PbSO_4$ is obtained. Inference: Confirms presence of Sulphate Radical. $BaCl_2$ Test: Experiment: Salt + $BaCl_2$ solution. Precipitate + conc. HCl. Observation: White precipitate obtained. White precipitate does not dissolve in conc. HCl. Inference: Confirms presence of Sulphate. 4. Chloride ($Cl^-$) Silver Nitrate Test: Experiment: O.S.S + dil $HNO_3$, boil, cool + silver nitrate solution. Precipitate + aqueous $NH_4OH$. Observation: White precipitate obtained. Precipitate dissolves in $NH_4OH$. Inference: Confirms presence of Chloride. Manganese Dioxide Test: Experiment: Salt + pinch of $MnO_2$ + conc. $H_2SO_4$, heat. Gas evolved tested with moist starch paper. Observation: Yellow or green gas with pungent smell evolved. Starch paper turns blue-black. Inference: Confirms presence of Chloride. Chromyl Chloride Test: Experiment: Salt + pinch of $K_2Cr_2O_7$ + few drops of conc. $H_2SO_4$, heat. Vapours collected in test tube, add NaOH solution. Yellow solution + Acetic acid + lead acetate. Observation: Reddish orange oily vapours (chromyl chloride) produced. Solution turns yellow. An yellow precipitate is obtained. Inference: Confirms presence of Chloride. 5. Phosphate ($PO_4^{3-}$) Ammonium Molybdate Test: Experiment: Salt + conc. $HNO_3$, boil + Ammonium Molybdate solution. Observation: An yellow precipitate is observed. Inference: May be presence of Phosphate. Magnesium Mixture Test: Experiment: O.S.S + solid $NH_4Cl$ + $MgCl_2$, boil, cool, add $NH_4OH$. Observation: White precipitate obtained. Inference: Confirms presence of Phosphate. Basic Radical Confirmatory Tests 1. Ammonium ($NH_4^+$) Nessler's Reagent Test: Experiment: O.S.S + NaOH + Nessler's reagent $K_2[HgI_4]$. Observation: Brown precipitate observed. Inference: Confirms presence of Ammonium. 2. Lead ($Pb^{2+}$) - Group I Potassium Chromate Test: Experiment: O.S.S + potassium chromate solution. Observation: An yellow precipitate is obtained. Inference: Confirms presence of $Pb^{2+}$. Golden Spangle Test: Experiment: O.S.S + potassium iodide solution. Mix precipitate with water and heat. Cool under tap water. Observation: An yellow precipitate is obtained. Precipitate dissolves on heating. Golden spangles are formed on cooling. Inference: Confirms presence of $Pb^{2+}$. 3. Aluminium ($Al^{3+}$) - Group III Ammonium Hydroxide Test: Experiment: O.S.S + $NH_4Cl$ + excess aqueous Ammonia. Observation: Gelatinous white precipitate observed. Inference: Confirms presence of $Al^{3+}$. Blue Lake Test: Experiment: O.S.S + $NH_4Cl$ + aqueous Ammonia + litmus solution. Observation: A blue lake is obtained above the gelatinous precipitate. Inference: Confirms presence of $Al^{3+}$. 4. Strontium ($Sr^{2+}$) - Group V Ammonium Sulphate Test: Experiment: O.S.S + Ammonium sulphate solution. Observation: White precipitate is obtained. Inference: Confirms the presence of Strontium. 5. Barium ($Ba^{2+}$) - Group V Ammonium Sulphate Test: Experiment: O.S.S + Ammonium Sulphate solution. Observation: White precipitate is obtained. Inference: Confirms the presence of $Ba^{2+}$. Ammonium Oxalate Test: Experiment: O.S.S + Ammonium oxalate solution. Observation: White precipitate is obtained. Inference: Confirms the presence of $Ba^{2+}$. Potassium Chromate Test: Experiment: O.S.S + potassium chromate solution. Observation: Yellow precipitate is obtained. Inference: Confirms the presence of $Ba^{2+}$. 6. Copper ($Cu^{2+}$) - Group II Ammonium Chloride/Ammonia Test: Experiment: O.S.S + Ammonium chloride + excess of aqueous Ammonia. Observation: Deep blue coloration. Inference: Confirms the presence of $Cu^{2+}$. Potassium Ferrocyanide Test: Experiment: O.S.S + potassium ferrocyanide. Observation: Chocolate brown precipitate. Inference: Confirms the presence of $Cu^{2+}$. 7. Nickel ($Ni^{2+}$) - Group IV Dimethyl Glyoxime Test: Experiment: O.S.S + Ammonium hydroxide solution + few drops of dimethyl glyoxime. Observation: Bright rose precipitate is obtained. Inference: Confirms the presence of $Ni^{2+}$. NaOH/Bromine Water Test: Experiment: O.S.S + NaOH in excess + Bromine water, boil. Observation: Black precipitate is obtained. Inference: Confirms the presence of $Ni^{2+}$. III. Intergroup Separation Preparation of Original Salt Solution (O.S.S) The given salt is soluble in water. Water extract is prepared. Group I (Pb$^{2+}$) Experiment: To O.S.S add dil HCl. Observation: A white precipitate is formed. Inference: Presence of Group I radical ($Pb^{2+}$). Group II (Pb$^{2+}$, Cu$^{2+}$) Experiment: To O.S.S, added dil HCl and $H_2S$. Observation: Black precipitate observed. Inference: Presence of Group II radical. Group III ($Al^{3+}$) Experiment: To O.S.S add $NH_4Cl$ and $NH_4OH$. Observation: Gelatinous white precipitate was observed. Inference: May be the presence of Group III radical. Group IV ($Ni^{2+}$) Experiment: To O.S.S add $NH_4Cl$, $NH_4OH$ and $H_2S$. Observation: Black precipitate was observed. Inference: May be the presence of Group IV radical. Group V ($Sr^{2+}$, $Ba^{2+}$) Experiment: To O.S.S add $NH_4Cl$, $NH_4OH$ and $(NH_4)_2CO_3$. Observation: White precipitate was observed. Inference: May be the presence of Group V radical.