Simple Salt Chemistry PDF

Scheme of acidic radicals Experiment Observation Result Salt + dil 1 Effervescence on cold, CO2 gas evolved CO3-2 or HCO3- HCl which render lime water turbid 2 SO2 gas suffocating odour on warming SO3 -2 turns acidi...

Scheme of acidic radicals Experiment Observation Result Salt + dil 1 Effervescence on cold, CO2 gas evolved CO3-2 or HCO3- HCl which render lime water turbid 2 SO2 gas suffocating odour on warming SO3 -2 turns acidified potassium dichromate paper in to green and solution is clear 3 SO2 gas suffocating odour on warming S2O3 -2 turns acidified potassium dichromate paper in to green and solution becomes (S + SO3 -2 ) yellow due to sulphide is ppt 4 H2S gas evolves on warming has odour S-2 like rotten eggs. And blackness lead acetate paper 5 NO2 gas evolves ,brown fumes and NO3 - solution turns faint blue 6 If no gas evolved Acidic radical is not from group I it may be from Gp II or Gp III Experiment Observation Result Salt + conc 1 HCl colourless gas evolves which gives Chloride, (Cl–) H2SO4 dense white fumes when a rod dipped in ammonium hydroxide is brought near the mouth of the test tube. 2 Mix of HBr and Br2 Reddish brown Bromide, (Br–) gases ,solution turns reddish brown 3 Mix of HF and I2Violet vapours, which Iodide, (I–) turn starch paper blue and a layer of violet sublimate is formed on the sides of the tube.(sulphur ppt on walls of tube) 4 NO2 Brown fumes evolve which become Nitrate, ( NO3–) dense upon heating the reaction mixture after addition of copper turnings and the solution becomes faint blue 5 If no gas evolved Acidic radical is not from group II it may be from Gp III Experiment Observation Result Salt solution 1 White ppt of insoluble in mineral SO42 – + BaCl2 acides solution (barium sulphate) 2 White ppt of soluble in mineral acides PO4-3 or B4O7-2 (barium phosphate) OR (barium metaborate)  Group III Acidic radicals (SO4 -2, PO4 -3, B4O7-2) 1. Test of Sulphate ions [SO42 –] Salt solution +Barium chlorides (BaCl2): White ppt of barium sulphate in soluble in mineral acides Confirmatory Tests [SO42 –] Concentrated Salt solution White ppt (Ag2SO4 ) +AgNO3 Salt solution +lead acetate White ppt soluble in ammonium acetate -NaOH 2. Test of phosphate ion [PO43 –] Salt solution +Barium chlorides (BaCl2): White ppt of barium phosphate soluble in mineral acides Confirmatory Tests [PO43 –] Salt solution +AgNO3 yellow ppt soluble in NH4OH Salt solution +FeCl3 Yellow ppt(FePO4 ) soluble in mineral acides Salt solution + exess of Canary yellow ppt ammonium molybdate +conc HNO3 and heat 3. Test of Borates ions [B4 O7 2–] Salt solution +Barium chlorides (BaCl2): White ppt of( Ba(BO2 )2 ) soluble in mineral acides Confirmatory Tests [B4 O7 2–] Concentrated of Salt White ppt AgBO2 solution +AgNO3 Salt solution +ph-ph Pink colour disappear with adding glycerol  Group II Acidic radicals (Cl- , Br- , I- , NO3 - ) 1. Test of chloride anion [Cl-] Solid+ a few drops of concentrated H2SO4 and warm : HCl evolves which is recognized by the formation of white clouds of ammonium chloride when a glass rod wetted with ammonia solution is held near the mouth of the tube. Confirmatory Tests [ Cl- ] Salt solution +AgNO3 White ppt (AgCl) soluble in dilute ammonia solution Concentrated Salt solution White ppt of lead chloride soluble +lead acetate in hot water 2. Test of bromide anion [Br-] Solid+ concentrated H2SO4 and warm : reddish-brown vapours of Br2 +HBr are evolved ,and the solution becomes reddish-brown in colour. Confirmatory Tests [ Br- ] Salt solution + AgNO3 Pale yellow ppt in soluble in dil HNO3 Salt solution +lead acetate White ppt soluble in boiling water 1. Test of Iodide anion [I-] Solid + concentrated H2SO4 and warm : violet vapours of I2 are evolved, which turn starch paper into blue. Confirmatory Tests [ I- ] Salt solution +AgNO3 yellow ppt in soluble in ammonia solution Salt solution +HgCl2 Scarlet red ppt of mercuric iodide soluble in excess of KI 1. Test of Nitrate anion [NO3–] Solid + concentrated H2SO4 and heat : Brown fumes of NO2 evolve which become dense upon heating the reaction mixture after addition of copper turnings and the solution acquires blue colour. Confirmatory Tests [NO3–] Salt solution +AgNO3 Pale yellow ppt Salt solution +FeSO4+ Brown ring conc H2SO4  Group I Acidic Radicals (CO2 3 – , HCO3– , S2–, SO3 -3 , S2O3 -2 ,NO3 - ) Group reagent is dil HCl 1. Test for Carbonate ion [CO2 3 –]and Bicarbonate[HCO3–] If there is effervescence with the evolution of a colourless and odourless gas on adding dil. HCl to the solid salt, this indicates the presence of carbonate ion. The gas turns lime water milky due to the formation of CaCO3 Na2CO3 + HCl NaCl+ H2O +CO2 Ca(OH)2 + CO2 CaCO3 + H2O Confirmatory Tests: (CO2 3 –) Salt solution +MgSO4 White ppt on cold (MgCO3) if no ppt on cold and.Boil the soln white ppt is formed Mg(CHO3)2 ( HCO3– ) Salt solution +HgCl2 Reddish brown ppt on cold(HgCO3.3HgO) if no ppt on cold.Boil the soln reddish brown ppt is formed Salt solution +BaCl2 White ppt (BaCO3) Salt solution+AgNO3 White ppt (Ag2CO3)  2. Test for Sulphide ion [S2–] With warm dilute HCl a sulphide gives hydrogen sulphide gas which smells like rotten eggs. A piece of filter paper dipped in lead acetate solution turns black on exposure to the gas due to the formation of lead sulphide which is black in colour. Na2S + HCl NaCl + H2S (CH3COO)2Pb + H2S PbS + 2CH3COOH Black precipitate Lead sulphide Confirmatory Tests: Sulphide ion Salt solution + Na4 [Fe(CN)5NOS] Complex of Purple colour (S2– ) Na2 [Fe(CN)5NO] Sodium nitroprusside Salt solution+ AgNO3 Black ppt is formed (Ag2s) Salt solution + Lead Black ppt of lead sulphide (PbS) acetate 3. Test for Sulphite ion [SO2 3 –] On treating Sulphite with warm dil. HCl, SO2 gas is evolved which is suffocating with the smell of burning Sulphur. Na2SO3 + HCl NaCl + H2O + SO2 The gas turns potassium dichromate paper acidified with dil. H2SO4, in to green and the solution becomes clear K2Cr2O7 + H2SO4 + 3SO2 K2SO4 + Cr2 (SO4)3 + H2O Chromium sulphate (green)    Confirmatory Tests: Sulphite ion Salt solution + barium white precipitate of barium sulphite. BaSO 3 [SO2 3 –] chloride solution (BaCl2) Salt solution + drops of Decolourisstion occurs acidified potassium permanganate solution Salt solution +Lead White ppt of lead Sulphite soluble in cold acetate diluteHNO3 4.Test for ThioSulphate ion [S2O3 2–] On treating Sulphite with warm dil. HCl, SO2 gas is evolved which is suffocating with the smell of burning sulphur. Na2S2O3 + HCl NaCl + S + SO2 The gas turns potassium dichromate paper acidified with dil. H2SO4, in to green and the solution becomes yellow  Confirmatory Tests: ThioSulphate ion Salt solution + barium white precipitate of barium [S2O3 2–] chloride solution thiosulphate. Salt solution +Lead White ppt of lead thiosulphate acetate (PbS2O3), on boiling black ppt is obtained. Salt solution +Ferric dark violet coloration disappears chloride solution after short time (FeCl3 ) 5. Test for nitrite ion [NO2–] On treating a solid nitrite with dil. HCl and warming, reddish brown fumes of NO 2 gas are evolved and solution becomes pale blue NaNO2 + HCl NaCl+ HNO2 3HNO2 HNO3 + 2NO + H2O 2NO + O2 2NO2 Brown gas  Confirmatory Tests: nitrite ion Salt solution + barium chloride no precipitate [NO2–] solution Salt solution + AgNO3 White ppt is formed Salt solution + FeSO4+ conc H2SO4 Brown ring is formed (FeSO4.NO) Salt solution + KMnO4+ drop of conc decolouration H2SO4  Group Ⅴ Basic radicals ( Ba2+ , Sr2+ , Ca2+ ) 1. Test of Barium Ion [Ba2+] Salt solution + ammonium chloride (NH4Cl ) + ammonium hydroxide (NH4OH) + ammonium carbonate (NH4)2 CO3 : White ppt of barium carbonate (BaCO3) Confirmatory Tests [Ba2+ ] Salt solution + potassium Yellow ppt of barium chromate chromate (K2CrO4) dissolving in mineral acids (BaCrO4) 5 drops of salt solution +4 White ppt of Barium oxalate drops of Ammonium (BaC2O4) oxalate solution Flame test Salt colors the flame yellowish green 2. Test of strontium Ion [Sr2+] Salt solution + ammonium chloride (NH4Cl ) + ammonium hydroxide (NH4OH) + ammonium carbonate (NH4)2 CO3 : White ppt of strontium carbonate (SrCO3) Confirmatory Tests [Sr2+ ] 6 drops of salt solution +6 White ppt of strontium oxalate drops of Ammonium (SrC2O4) oxalate solution  Flame test Salt colors the flame crimson color 3. Test of calcium Ion [Ca2+] Salt solution + ammonium chloride (NH4Cl ) + ammonium hydroxide (NH4OH) + ammonium carbonate (NH4)2 CO3 : White ppt of Calcium carbonate (CaCO3) Confirmatory Tests [Ca2+ ] 6 drops of salt solution +6 White ppt of calcium oxalate drops of Ammonium (CaC2O4) oxalate solution Flame test Salt colors the flame brick- red color  Group Ⅵ Basic radicals ( NH4+ , K+ , Mg2+ , Na+ ) 1. Test of Ammonium Ion [NH4+] [NH4+ ] Salt solution + (NaOH) NH3 gas evolved and if expose to solid and solution then glass rod wetted by HCl ,it form boiling white fumes Salt solution +sodium Yellow ppt of ammonium cobalt cobalt nitrite nitrite (NH4)3[Co(NO2)6] Na3[Co(NO2)6] 2. Test of Potassium Ion [K+] [K+ ] Salt solution +sodium Yellow ppt of Potassium cobalt cobalt nitrite nitrite K3[Co(NO2)6] Na3[Co(NO2)6] Flame test Salt colors the flame violet color 3. Test of Magnesium Ion [Mg2+] [Mg2+ ] Salt solution + NH4Cl White ppt of Magnesium +NH4OH + Disodium ammonium phosphate hydrogen phosphate Mg (NH4)PO4 (Na2HPO4) Salt solution + NaoH White ppt of magnesium hydroxide Mg(OH)2 4. Test of Sodium Ion [Na+] [Na+ ] Flame test Salt colors the flame golden yellow color  Group III Cations Cr3+, Al3+ , Fe2+,Fe3+ Group reagent: buffer (NH4Cl + NH4OH) Precipitation Form : as hydroxide 1-Test for Chromic ion Cr3+ Soln of chromic nitrate +buffer Pale green ppt Cr(OH)3 CrCl3 + 3NH4OH Cr(OH)3 + 3NH4Cl (Cr3+) Soln+ Na2O2 Yellow soln (CrO4)2- Sodium Peroxide Soln + NaOH Pale green Cr(OH)3 2-Test for Aluminium Ion Al3+ Soln of aluminium nitrate + buffer gelatinous white ppt Al(OH)3 Al3+ +3NH4OH Al(OH)3+3NH4 (Al3+) Soln + NaOH White ppt Al(OH)3 Soln + (NH4)2SO4 White ppt Al(OH)3 not Ammonium Sulphide aluminium sulphide which decomposes by hydrolysis. 3-Test for Ferrous Ion Fe2+ Soln of ferrous ammonium sulphate + buffer soln green ppt Fe(OH)2 Soln + K4[Fe(CN)6] Pale blue ppt Fe2[Fe(CN)6] 2+ Potassium ferrocyanide (Fe ) Soln + K3[Fe(CN)6] Dark blue ppt Fe3[Fe(CN)6]2 Potassium ferricyanide 4-Test for Ferric ion Fe3+ Soln of Ferric Chloride + buffer soln brown ppt Fe(OH)3 (Fe3+) Soln+ NaOH Brown ppt Soln + K4[Fe(CN)6] Dark blue Fe4[Fe(CN)6]3  Group Ⅳ Basic radicals ( Mn2+ , Ni2+ , Co2+ , Zn2+) 1. Test of manganous Ion [Mn2+] Salt solution + ammonium chloride (NH4Cl ) + ammonium hydroxide (NH4OH) + Hydrogen sulphide (H2S) : Buff ppt of Manganese sulfide (MnS) Confirmatory Tests [Mn2+ ] Salt solution +NaOH White ppt of manganous hydroxide Mn(OH)2 insoluble in excess of the reagent. Salt solution + Disodium White ppt of Manganese(II) hydrogen phosphate Hydrogen Phosphate ( MnHPO4) (Na2HPO4) 2. Test of Nickel Ion [Ni2+] Salt solution + ammonium chloride (NH4Cl ) + ammonium hydroxide (NH4OH) + Hydrogen sulphide (H2S): Black ppt of nickel sulphide (NiS) in soluble in mineral acid and soluble in aqua regia (conc HNO3 :concHCl) Confirmatory Tests [Ni 2+] Salt solution +NaOH Green ppt of nickel hydroxide Ni(OH)2 insoluble in excess of the reagent. Salt solution + NH4OH + Red ppt of Nickel Dimethylglyoxime dimethylglyoxime Ni(D.M.G)2 (D.M.G) 3. Test of cobalt Ion [Co2+] Salt solution + ammonium chloride (NH4Cl ) + ammonium hydroxide (NH4OH) + Hydrogen sulphide (H2S): Black ppt of cobalt sulphide (CoS) in soluble in mineral acid and soluble in aqua regia (conc HNO3 :concHCl) Confirmatory Tests [Co2+] Salt solution +NaOH Blue ppt change on warming with excess of NaOH to pink Co(oH)2 Salt solution + Ammonium Blue solution due to the thiocyanate (NH4SCN) formation of a complex salt of +drop of alcohol ammonium cobalt thiocyanate (NH4)2Co(CNS)4 4. Test of Zinc Ion [Zn2+] Salt solution + ammonium chloride (NH4Cl ) + ammonium hydroxide (NH4OH) + Hydrogen sulphide (H2S): white ppt of Zinc sulphide (ZnS). Confirmatory Tests [Zn2+] Salt solution +NaOH White ppt of Zinc hydroxide Zn(OH)2 soluble in excess of the reagent. Salt solution + potassium White ppt of Zinc ferrocyanide ferrocyanide K4[Fe(CN)6] Zn2 [Fe(CN)6]  Group I Basic Radicals (Pb++, Ag+, Hg2++) Group reagent is dil HCl Precipitation form as chlorides 1-Test for lead cation [Pb++] Soln of lead nitrate +dil HCl White precipitate of lead chloride (PbCl2) on cold, the ppt dissolves in hot water. Pb(NO3)2 + 2HCl PbCl2 + 2HNO3 Confirmatory Tests: (Pb++) Soln + KI Yellow ppt (PbI2), which soluble in hot water and on cold give golden crystals. Soln + Yellow ppt of (PbCrO4) which K2CrO4 soluble in alkali hydroxides and in nitric acid and insoluble in acetic acid. 2-Test for Mercurous cation[Hg2]2+ Soln of mercurous nitrate + dil HCl White ppt of (Hg2Cl2), which insoluble in hot water. Hg2(NO3)2 + 2HCl Hg2Cl2 + 2HNO3 The ppt becomes black by addition of ammonia due to formation of amino-mercuric chloride (white) and finally divided mercury (black). This black mixture is soluble in aqua regia (conc HNO3: conc HCl 1:3) forming mercuric chloride. Confirmatory Tests: (Hg2)2+ Soln + KI Yellow ppt (Hg2I2), which soluble in excess of KI forming complex K2[HgI4]. Soln+K2CrO4 Brown ppt of (Hg2CrO4) in cold. 3-Test for silver cation [Ag+] Soln of Silver nitrate + dil HCl White ppt (AgCl) AgNO3 + HCl AgCl +HNO3 Confirmatory Tests: [Ag+] Soln + KI Yellow ppt of (AgI). Soln + K2CrO4 Scarlet red ppt (Ag2CrO4), which soluble in dil nitric acid.  Group II Cations of group II are characterized by their precipitation as sulphides with H 2S in acid medium (dil HCl). Dilute HCl is added to decrease the concentration of sulphide ion,S 2- by common ion effect. The conc of S2- ions will be just enough to precipitate the sulphides of this group (when solubility product constant is very low) but not sulphides of the subsequent groups (where solubility product constants are much higher). Group II Group IIA Group IIB (Hg2+), (Bi3+),(Cu2+),(Cd2+) that is (As3+),(As5+),(Sb5+),(Sn2+,Sn4+) metals whose sulphides are that is metals whole sulphides insoluble in yellow ammonium are soluble in yellow amm sulphide or sodium hydroxide. sulphide and in sodium hydroxide. GroupIIA 1-Test for mercuric ion Hg2+ Soln of mercuric chloride+H2S+dil HCl White then brown and finely ablack ppt (HgS). 3HgCl2 + 2H2S Hg3S2Cl2 + 4HCl (white) Hg3S2Cl2 + H2S 3HgS + 2HCl (black) Confirmatory Tests: (Hg2+) Soln+NH4OH White ppt Hg(NH2)Cl. Soln+NaOH Yellow ppt HgO. 2-Test for Cupric ion Cu2+ Soln of cupric sulphate +dil HCl+H2S black ppt of CuS. CuSO4 + H2S CuS + H2SO4 (Cu2+) Soln+NaOH Blue ppt of Cu(OH)2 Soln+NH4OH Pale blue ppt of basic salt,soluble in excess of the reagent with the formation of deep blue solution Cu(NH3)4SO4 3-Test for Cadmium ion Cd2+ Soln of Cadmium Sulphate +dil HCl+H2S Yellow ppt of CdS (Cd2+) Soln+NaOH White ppt Cd(OH)2 Soln+NH4OH White ppt Cd(OH)2,which soluble in excess of the reagent. 4- Test for Bithmuth Ion Bi3+ Soln of bithmuth nitrate +dil HCl+H2S brown ppt Bi2S 3 2Bi(NO3)3+ 3H2S Bi2S3 + 6HNO3 (Bi3+) Soln+NaOH White ppt Bi(OH)3  Soln+NH4OH White ppt Group II-B 1-Test for stannous ions Sn2+ Soln stannous chloride +dil HCl+H2S brown ppt SnS (Sn2+) Soln+NaOH White ppt Sn(OH)2 Soln+HgCl2 White ppt 2-Test for stannic ion Sn4+ Soln of stannic chloride +dil HCl+H2S yellow ppt (Sn4+) Soln+NaOH White gelatinous ppt Sn(OH)4,soluble in excess of NaOH Soln+HgCl2 No preciptate 3-Test for Antimonious ion Sb3+ Soln of antimony trichloride +H2S+dil HCl orange ppt Sb2S3 2SbCl3 + 3H2S Sb2S3 + 6HCl (Sb3+) Soln+NaOH White ppt