Free NEET Chemistry multiple-choice questions on Salt Analysis: Cations. Attempt each question and reveal the answer with a full explanation.
Paper chromatography is an example of which type of chromatography? Partition chromatography Adsorption chromatography Thin layer chromatography Column chromatography The most suitable method for the separation of a mixture of aniline and water is: Steam distillation Fractional distillation Simple distillation Distillation under reduced pressure In the qualitative analysis of Group IV cations, H 2S is passed in an alkaline medium because: High concentration of S 2- is needed to exceed the K sp of Group IV sulfides It prevents the precipitation of Group II sulfides It increases the solubility of the cations It stabilizes the NH 4OH reagent During the Carius method for chlorine estimation, 0.20 ,g of an organic compound gave 0.287 ,g of AgCl . The percentage of chlorine is: [Atomic mass: Ag=108, Cl=35.5 ] 35.5% 71.0% 17.75% 25.0% H2S gas when passed through a solution of cations containing HCl precipitates the cations of second group of qualitative analysis but not those belonging to the fourth group. It is because- Presence of HCl decreases the sulphide ion concentration. Sulphides of group IV cations are unstable in HCl Solubility product of group II sulphides is more than that of group IV sulphides Presence of HCl increases the sulphides ion concentration Match List I with List II array llll ; & List-I (Ion) & ; & List-II (Group Number in Cation Analysis) A. & Co 2+ & I. & Group-I B. & Mg 2+ & II. & Group-III C. & Pb 2+ & III. & Group-IV D. & Al 3+ & IV. & Group-VI array Choose the correct answer from the options given below : A-III, B-II, C-I, D-IV A-III, B-IV, C-II, D-I A-III, B-IV, C-I, D-II A-III, B-II, C-IV, D-I In the systematic analysis of cations, why is H 2S gas passed in the presence of dilute HCl for Group II? To suppress the ionization of H 2S To increase the ionization of H 2S To keep the pH basic To oxidize the cations In the detection of halogens using Lassaigne's test, why is the sodium fusion extract boiled with concentrated HNO 3 before adding AgNO 3 ? To decompose NaCN and Na 2S To oxidize the halides To make the solution basic To increase the sensitivity of the test In systematic qualitative analysis, yellow ammonium sulfide (YAS) is used to separate: Group IIA from Group IIB Group I from Group II Group III from Group IV Group II from Group III In the precipitation of Group III cations ( Al 3+ , Fe 3+ , Cr 3+ ), the role of adding NH 4Cl before NH 4OH is to: Suppress the ionization of NH 4OH by common ion effect Increase the concentration of OH - ions Act as a catalyst for precipitation Maintain a basic pH above 12 In the systematic analysis of Group II cations, Cd 2+ is identified by the formation of a yellow precipitate with H 2S gas. If the solution is too acidic, the precipitate might not form because: The concentration of S 2- ions becomes too low to exceed the K sp of CdS . CdS is soluble in concentrated HCl . Cd 2+ reacts with HCl to form a stable complex. The K sp of CdS increases in acidic medium. In the analysis of Group IV cations, Ni 2+ is precipitated as NiS and then identified using Dimethylglyoxime (DMG). The structure of the resulting nickel-DMG complex involves: Chelation with hydrogen bonding Simple ionic bonding Only coordinate covalent bonds without rings -bonding with the metal An unknown salt produces an 'Apple Green' color in the flame test. The cation is most likely: Ba 2+ Sr 2+ Ca 2+ Cu 2+ During the identification of Group II cations, if the concentration of HCl is too high (greater than 0.3M ), which of the following cations might fail to precipitate as its sulfide? Cd 2+ Hg 2+ Cu 2+ Bi 3+ Which cation in qualitative analysis forms a black precipitate with NH 4OH that is actually a mixture of metallic mercury and amino-mercuric chloride? Hg 2 2+ Hg 2+ Ag + Pb 2+ During the analysis of Group V cations ( Ba 2+ , Sr 2+ , Ca 2+ ), the group reagent is (NH 4) 2CO 3 in the presence of NH 4Cl and NH 4OH . The role of NH 4Cl is to: Suppress the ionization of (NH 4) 2CO 3 to prevent precipitation of Mg 2+ Increase the concentration of CO 3 2- ions Keep the medium acidic Increase the solubility of Group V carbonates In the systematic analysis of Group II cations, the separation of Cu 2+ and Cd 2+ is achieved by adding excess KCN followed by passing H 2S gas. Which of the following statements is correct? Cd 2+ precipitates as yellow CdS because [Cd(CN) 4] 2- is less stable than [Cu(CN) 4] 3- Cu 2+ precipitates as black CuS because [Cu(CN) 4] 2- is less stable Cd 2+ does not precipitate because [Cd(CN) 4] 2- is extremely stable Both Cu 2+ and Cd 2+ precipitate as their respective sulfides In the Sodium Nitroprusside test for sulfur, the purple complex formed is [Fe(CN) 5NOS] 4- . The oxidation state of Iron in this complex is: +2 +3 +1 0 In the qualitative analysis of Group IIB, arsenic ( As 3+ ) is identified by the formation of a yellow sulfide ( As 2S 3 ). This sulfide is uniquely soluble in: (NH 4) 2CO 3 solution Dilute HCl Cold water Dilute CH 3COOH During the Group IV analysis, Zn 2+ and Mn 2+ are precipitated as sulfides. How are they separated? By adding dilute HCl , which dissolves MnS but not ZnS By adding NaOH , which dissolves ZnS By adding NH 4OH , which dissolves MnS By heating, which causes ZnS to sublime In the 'Lassaigne's test', if the sodium fusion extract is not boiled with concentrated HNO 3 before adding AgNO 3 , what error might occur? CN - and S 2- might produce precipitates that interfere with the halide test The silver halides will become more soluble The sodium extract will explode upon adding silver nitrate The color of the halides will change from white to red Which of the following chlorides does NOT respond to the Chromyl Chloride test? HgCl 2 NaCl KCl CaCl 2 Which of the following describes the correct observation when Fe 2+ ions react with potassium ferricyanide ( K 3[Fe(CN) 6] )? Formation of Turnbull's blue precipitate Formation of Prussian blue precipitate Formation of a blood-red solution Formation of a brown ring A salt solution gives a black precipitate with lead acetate paper. This confirms the presence of: S 2- SO 4 2- Cl - CO 3 2- In the separation of Group V cations ( Ba 2+ , Sr 2+ , Ca 2+ ), Ba 2+ is first separated as its chromate. Which condition is necessary for this precipitation? In the presence of acetic acid In the presence of HCl In the presence of NaOH In the presence of NH 4OH During the identification of As 3+ , Sb 3+ , and Sn 4+ in Group IIB, the sulfides are dissolved in yellow ammonium sulfide. Which of the following ions is formed in the solution when As 2S 3 dissolves? AsS 4 3- As 3+ AsO 4 3- As 2S 5 Magneson-II reagent, used for the detection of Mg 2+ ions, is chemically: 4-(4-Nitrophenylazo)-1-naphthol p-Nitrobenzeneazoresorcinol Dimethylglyoxime Ammonium carbonate In the Carius method, 0.12 ,g of an organic compound containing phosphorus gave 0.222 ,g of Mg 2P 2O 7 . The percentage of phosphorus in the compound is: [Atomic mass: Mg=24, P=31, O=16 ] 51.66% 25.83% 31.00% 62.00% In Group III of cation analysis, Cr 3+ is precipitated as a hydroxide of which color? Green Reddish-brown White Blue The purpose of a fractionating column in fractional distillation is: To provide a large surface area for repeated condensation and vaporization To increase the pressure inside the flask To decrease the boiling point of the liquid To prevent the liquid from bumping Chloroform and aniline can be separated by: Distillation Sublimation Crystallization Chromatography When a solution of potassium salt is treated with sodium cobaltinitrite reagent in the presence of acetic acid, a yellow precipitate is formed. What is the chemical formula of this precipitate? K 2Na[Co(NO 2) 6] or K 3[Co(NO 2) 6] K 3[Co(CN) 6] Na 3[Co(NO 2) 6] K 2[Co(NO 2) 4] Zinc ( Zn 2+ ) forms a white gelatinous precipitate with NaOH , which dissolves in excess of the reagent. This dissolution occurs due to the formation of: [Zn(OH) 4] 2- Zn(OH) 2 ZnO [Zn(H 2O) 4] 2+ The lilac (violet) flame observed during the flame test is characteristic of which metal ion? K + Na + Li + Ba 2+ A mixture of camphor and common salt ( NaCl ) can be separated by: Sublimation Crystallization Distillation Filtration Dimethylglyoxime (DMG) is used for the identification and estimation of which cation in an alkaline medium? Ni 2+ Co 2+ Mn 2+ Fe 2+ A mixture of two volatile liquids with boiling points 350 K and 355 K can be best separated by: Fractional distillation Simple distillation Steam distillation Vacuum distillation In the chromatography process, the 'Stationary Phase' in Thin Layer Chromatography (TLC) is typically: Silica gel or Alumina Water held in cellulose A liquid solvent An inert gas The method of 'Differential Extraction' is based on the difference in which property of the solute in two immiscible solvents? Solubility Boiling point Vapor pressure Molecular mass A Thiele tube is specifically designed for the determination of: Melting points and boiling points Concentration of solutions Surface tension of liquids Viscosity of oils During the flame test, a salt of Strontium produces which characteristic color? Crimson red Brick red Apple green Lilac In the systematic qualitative analysis of cations, which of the following is known as the 'Group 0' cation and is primarily identified using Nessler's reagent? NH 4 + K + Na + Li + In partition chromatography, which of the following represents the stationary phase? A liquid film supported on an inert solid A solid adsorbent like silica gel A gas A reactive chemical solution Which reagent is used for the detection of potassium ( K + ) ions in qualitative analysis, resulting in a yellow precipitate? Sodium cobaltinitrite Potassium ferrocyanide Ammonium molybdate Magnesia mixture In the process of purification by crystallization, the impure solid is dissolved in a solvent. Which of the following conditions is ideal for the solvent? High solubility at high temperature and low solubility at low temperature Equal solubility at all temperatures Low solubility at high temperature and high solubility at low temperature High solubility at all temperatures During the identification of Group I cations, Pb 2+ is precipitated as PbCl 2 . Which of the following reagents is used to confirm Pb 2+ by forming a yellow precipitate that is soluble in NaOH ? K 2CrO 4 KI H 2S (NH 4) 2SO 4 Starch-Iodide paper is used to test for the presence of: Oxidizing agents Reducing agents Acids Bases Which of the following elements do NOT impart any color to the flame during the flame test because of their high ionization enthalpies? Be and Mg Ca and Sr Ba and K Li and Na The separation of a mixture of I 2 and NaCl is best achieved by: Sublimation Crystallization Steam distillation Fractional distillation In the purification of organic compounds, 'Glycerol' is separated from spent-lye in the soap industry by which method? Distillation under reduced pressure Steam distillation Fractional distillation Differential extraction When Hg 2+ salt solution is treated with KI dropwise, a scarlet red precipitate is formed. What is the formula of this precipitate? HgI 2 K 2[HgI 4] Hg 2I 2 HgI In the qualitative analysis of Group IIB, the complex formed when Cd 2+ reacts with excess KCN is: [Cd(CN) 4] 2- [Cd(CN) 6] 4- Cd(CN) 2 [Cd(CN) 4] 3- Given below are certain cations. Using inorganic qualitative analysis, arrange them in increasing group number from 0 to VI. A. Al 3+ B. Cu 2+ C. Ba 2+ D. Co 2+ E. Mg 2+ Choose the correct answer from the options given below. B, A, D, C, E B, C, A, D, E E, C, D, B, A E, A, B, C, D In the Lassaigne's test for the detection of nitrogen in an organic compound, the appearance of a Prussian blue color is due to the formation of which complex? Fe 4[Fe(CN) 6] 3 [Fe(CN) 6] 4- [Fe(CN) 6] 3- Fe 3[Fe(CN) 6] 2 In the Lassaigne's test, if both nitrogen and sulfur are present in an organic compound, which complex is responsible for the blood-red color upon adding FeCl 3 ? [Fe(SCN)] 2+ [Fe(CN) 6] 3- Fe 4[Fe(CN) 6] 3 [Fe(SCN) 3] In the estimation of nitrogen by Kjeldahl's method, the nitrogen present in the organic compound is converted into: (NH 4) 2SO 4 (NH 4) 3PO 4 (NH 4) 2CO 3 (NH 4)Cl Which cation belongs to Group III of qualitative analysis and forms a gelatinous white precipitate with NH 4OH in the presence of NH 4Cl ? Al 3+ Fe 3+ Cr 3+ Zn 2+ In Thin Layer Chromatography (TLC), the stationary phase is generally: Silica gel Water Ethanol Alumina beads The 'Borax Bead Test' is not suitable for which of the following? Al 3+ Cu 2+ Cr 3+ Mn 2+ In qualitative analysis, Group V cations ( Ba 2+ , Sr 2+ , Ca 2+ ) are precipitated as their: Carbonates Sulfides Hydroxides Chlorides What is the color of the precipitate formed when Cu 2+ ions react with potassium ferrocyanide? Chocolate brown Deep blue White Yellow In the precipitation of Group IV cations ( Zn 2+ , Mn 2+ , Ni 2+ , Co 2+ ), the medium is kept: Basic Acidic Neutral Highly acidic ( pH < 1 ) In the Dumas method for the estimation of nitrogen, the purpose of the oxidized copper gauze used at the end of the combustion tube is to: Reduce oxides of nitrogen back to free nitrogen gas Absorb carbon dioxide gas Increase the temperature of the combustion Oxidize the organic compound completely In the detection of NH 4 + ion using Nessler's reagent, the brown precipitate formed is chemically known as: Iodide of Millon's base Potassium tetraiodomercurate(II) Mercuric oxide Ammonium tetraiodomercurate(II) The chemical formula of the Prussian blue precipitate formed in the detection of Fe 3+ ions with potassium ferrocyanide is: Fe 4[Fe(CN) 6] 3 Fe 3[Fe(CN) 6] 4 KFe[Fe(CN) 6] Fe[Fe(CN) 6] Which of the following silver halides is only sparingly soluble in dilute NH 4OH but readily soluble in concentrated NH 4OH ? AgBr AgCl AgI AgF In the Cobalt Nitrate test, a blue colored mass (Thenard's blue) indicates the presence of which metal ion? Al 3+ Zn 2+ Mg 2+ Cu 2+ What is the chemical formula of Microcosmic salt used in bead tests? Na(NH 4)HPO 4 4H 2O Na 2HPO 4 12H 2O Na 3PO 4 12H 2O NH 4H 2PO 4 Which of the following reagents is used to identify the presence of NH 4 + ions in salt analysis? Nessler's reagent Tollen's reagent Fehling's solution Schiff's reagent During the analysis of Group I cations ( Pb 2+ , Ag +, Hg 2 2+ ), which reagent is used to separate PbCl 2 from the other two precipitates? Hot water Dilute HNO 3 Ammonium hydroxide Potassium iodide During the estimation of nitrogen in an organic compound by Kjeldahl's method, what is the role of K 2SO 4 and CuSO 4 in the digestion process? K 2SO 4 raises the boiling point of H 2SO 4 , and CuSO 4 acts as a catalyst. K 2SO 4 acts as a catalyst, and CuSO 4 raises the boiling point. Both act as reducing agents to convert nitrogen to ammonia. Both act as oxidizing agents to remove carbon and hydrogen. In qualitative analysis, why is Pb 2+ included in both Group I and Group II? Because PbCl 2 is partially soluble in cold water and remains in the filtrate. Because Pb 2+ forms a yellow precipitate with K 2CrO 4 in both groups. Because Pb 2+ is the only cation that forms a sulfide in acidic medium. Because PbCl 2 is only soluble in concentrated HCl . The 'Lake Test' for Al 3+ ions involves the formation of a blue-colored floating mass in a solution containing: NH 4OH and Litmus solution NH 4OH and Phenolphthalein NaOH and Methyl orange Conc. HNO 3 and AgNO 3 In the estimation of phosphorus using the Carius method, the phosphorus present is converted into H 3PO 4 , which is then precipitated as: MgNH 4PO 4 Ag 3PO 4 P 2O 5 Ca 3(PO 4) 2 Which cation from Group IV forms a white precipitate with H 2S in the presence of NH 4Cl and NH 4OH ? Zn 2+ Mn 2+ Ni 2+ Co 2+ The oxidation of Mn 2+ to purple MnO 4 - by lead dioxide ( PbO 2 ) and concentrated HNO 3 is a test for: Manganese Lead Nitrate Peroxide Glycerol is purified by which of the following processes? Distillation under reduced pressure Steam distillation Fractional distillation Simple distillation In column chromatography, the sequence in which various compounds are eluted from the column depends on their: Adsorption preferences on the stationary phase Solubility in the mobile phase only Molecular weights Boiling points In the systematic analysis of cations, a white crystalline precipitate is obtained when a solution of the salt is treated with Na 2HPO 4 in the presence of NH 4OH and NH 4Cl . This indicates the presence of: Mg 2+ Ca 2+ Ba 2+ Sr 2+ A mixture of PbCl 2 , AgCl , and Hg 2Cl 2 can be separated by using hot water to selectively dissolve: PbCl 2 AgCl Hg 2Cl 2 None of these What is the chemical composition of the bead formed during the Borax Bead Test? NaBO 2 + B 2O 3 Na 3BO 3 Na 2B 4O 7 B 2O 3 only The formation of 'Golden Spangles' is a characteristic test for which ion when treated with KI solution? Pb 2+ Ag + Hg 2+ Cu 2+ In the Cobalt Nitrate test, a green residue (Rinmann's green) is obtained. This indicates the presence of which metal ion? Zn 2+ Al 3+ Mg 2+ PO 4 3- A white turbidity or precipitate is observed when a salt solution containing Bi 3+ ions is largely diluted with water. This is due to the formation of: Bismuth oxychloride ( BiOCl ) Bismuth hydroxide ( Bi(OH) 3 ) Bismuth oxide ( Bi 2O 3 ) Bismuth nitrate ( Bi(NO 3) 3 ) Addition of potassium iodide ( KI ) solution to a solution of Hg 2+ ions produces a scarlet red precipitate that dissolves in excess KI to form a colorless solution. The colorless solution contains the complex: [HgI 4] 2- HgI 2 [HgI 2] 2- K[HgI 3] Manganese ( Mn 2+ ) ions can be detected by heating the salt with concentrated HNO 3 and sodium bismuthate ( NaBiO 3 ). The appearance of a purple color is due to the formation of: MnO 4 - MnO 2 Mn 2O 7 MnO 4 2- In Group III cation analysis, the green precipitate of Cr(OH) 3 dissolves in a mixture of NaOH and H 2O 2 to form a yellow solution. This change is due to the oxidation of Cr 3+ to: CrO 4 2- Cr 2O 7 2- CrO 5 CrO 2 Which of the following sulfides is orange in color and belongs to Group IIB of cation analysis? Sb 2S 3 As 2S 3 SnS 2 CdS A salt solution gives a white precipitate with ammonium oxalate ( NH 4) 2C 2O 4 in the presence of NH 4OH . The precipitate is insoluble in acetic acid but soluble in dilute HCl . The cation is: Ca 2+ Ba 2+ Sr 2+ Mg 2+ In the Cobalt Nitrate test, Mg 2+ ions produce a residue of which color on the charcoal block? Pink Blue Green White Which of the following cations produces a 'Brick Red' flame during the flame test? Ca 2+ Sr 2+ Ba 2+ K + In the estimation of phosphorus by the Carius method, the phosphorus is eventually weighed as: Mg 2P 2O 7 P 2O 5 H 3PO 4 Mg 3(PO 4) 2 In the Kjeldahl method, the ammonia evolved from the organic compound is absorbed in a known volume of standard: H 2SO 4 (excess) NaOH (excess) KOH (excess) Distilled water In the estimation of phosphorus using the Carius method, the phosphorus in the organic compound is eventually precipitated and weighed as: Mg 2P 2O 7 Mg(NH 4)PO 4 P 2O 5 H 3PO 4 In the systematic analysis of cations, why is concentrated HNO 3 added to the filtrate of Group II before proceeding to Group III? To oxidize Fe 2+ to Fe 3+ To precipitate Al 3+ as Al(NO 3) 3 To increase the solubility of S 2- ions To remove NH 4Cl In the estimation of nitrogen by the Dumas method, the nitrogen gas evolved is collected over an aqueous solution of KOH . The volume of the nitrogen gas must be corrected for: Aqueous tension Viscosity of KOH Surface tension of water Density of KOH In the separation of Group IIA and Group IIB cations, which reagent is used to dissolve the sulfides of Group IIB ( As, Sb, Sn )? Yellow Ammonium Sulfide Dilute HCl Concentrated HNO 3 Ammonium Hydroxide Which of the following salts gives a white residue that glows with a brilliant light (incandescence) when heated on a charcoal block in the presence of Na 2CO 3 ? Zn 2+ Cu 2+ Pb 2+ Fe 3+ In the detection of sulfur using the Sodium Nitroprusside test, the purple color is due to the formation of which complex? [Fe(CN) 5NOS] 4- [Fe(CN) 6] 4- [Fe(CN) 5NO] 2- [Fe(SCN)] 2+ In qualitative analysis, NH 4Cl is added before NH 4OH in Group III. If NH 4Cl is not added, which of the following might happen? Magnesium and Manganese might precipitate as hydroxides. No precipitate will form for Iron or Aluminum. The solution will become too acidic. The Group III cations will stay in solution as complexes. In the Victor Meyer's method for determining the molar mass of a volatile organic compound, the volume of air displaced is measured. The displaced air is collected over: Water in a graduated tube Mercury in a barometer Concentrated H 2SO 4 An empty flask at STP The deep blue color produced when Cu 2+ salt reacts with excess NH 4OH is due to the complex: [Cu(NH 3) 4] 2+ [Cu(NH 3) 6] 2+ [Cu(H 2O) 4] 2+ [Cu(OH) 4] 2- The R f value in chromatography is independent of which of the following? The length of the stationary phase The nature of the solvent The nature of the compound The temperature When SnCl 2 is added dropwise to a solution of HgCl 2 , the sequence of observations is: A white precipitate turning grey A black precipitate turning white An orange precipitate turning yellow A green precipitate turning blue In the gravimetric estimation of Barium as BaSO 4 , why is a small amount of dilute HCl added before adding H 2SO 4 ? To prevent the precipitation of other anions like CO 3 2- or PO 4 3- To increase the solubility of BaSO 4 To act as a catalyst for the reaction To reduce Ba 2+ to Ba + Which of the following describes the color change of a solution containing chromate ( CrO 4 2- ) and dichromate ( Cr 2O 7 2- ) ions as the pH is increased from 2 to 10? Orange to Yellow Yellow to Orange Orange to Green Colorless to Orange Which gas is evolved when a solid chloride salt is heated with MnO 2 and concentrated H 2SO 4 ? Cl 2 (Greenish-yellow gas) HCl (Colorless gas) CrO 2Cl 2 (Red vapors) O 2 (Colorless gas) In the analysis of Group I cations, when NH 4OH is added to the precipitate of AgCl and Hg 2Cl 2 , the Hg 2Cl 2 turns: Black Yellow Remains white Dissolves to form a colorless solution In the systematic analysis of Group III cations ( Fe 3+ , Al 3+ , Cr 3+ ), NH 4Cl is added before NH 4OH to: Suppress the dissociation of NH 4OH via common ion effect Increase the solubility of the hydroxides Act as a catalyst for precipitation Ensure the oxidation of ferrous to ferric ions In qualitative cation analysis, which of the following sulfides is orange in color? Sb 2S 3 CdS ZnS PbS Which of the following ions produces a black precipitate with H 2S gas in a dilute HCl medium? Cu 2+ Zn 2+ Al 3+ Ba 2+ In the 'Lake Test' for Aluminum ( Al 3+ ), the blue precipitate is due to the adsorption of litmus by: Al(OH) 3 Al 2(SO 4) 3 AlCl 3 Na[Al(OH) 4] A salt gives a crimson red color in the flame test. The cation present in the salt is likely: Sr 2+ Ba 2+ Ca 2+ K + In the detection of nitrogen by Lassaigne's test, why is the sodium extract boiled with FeSO 4 and then acidified with concentrated H 2SO 4 ? To form Prussian blue complex [Fe 4[Fe(CN) 6] 3] To oxidize Fe 2+ to Fe 3+ To convert NaCN to HCN To remove impurities from the extract In the qualitative analysis of Group V ( Ba 2+ , Sr 2+ , Ca 2+ ), the precipitated carbonates are dissolved in which acid for further identification? Acetic acid Hydrochloric acid Sulfuric acid Nitric acid In Volhard's method for the estimation of halides, which of the following ions is used as an indicator to detect the end point? Fe 3+ CrO 4 2- MnO 4 - Cu 2+ In the Borax bead test, which of the following metal ions gives a blue color bead in both oxidizing and reducing flames? Co 2+ Cu 2+ Fe 2+ Ni 2+ During the identification of Group II cations, the addition of H 2S produces a chocolate-brown precipitate. The cation is: Cu 2+ Pb 2+ Bi 3+ Sn 2+ The reaction between Cu 2+ and KI produces a white precipitate and a brown solution. The white precipitate is: Cu 2I 2 CuI 2 CuI K 2[CuI 4] A student places a clean copper wire into a solution of a Group I cation salt. A silvery-gray coating is formed on the wire. This indicates the presence of: Hg 2 2+ Ag + Pb 2+ Bi 3+ During the separation of Group II cations, the addition of excess NH 4OH to a solution containing Cu 2+ and Bi 3+ results in: Precipitation of Bi(OH) 3 and dissolution of Cu(OH) 2 Precipitation of both Bi(OH) 3 and Cu(OH) 2 Dissolution of both hydroxides Precipitation of Cu(OH) 2 only In Gas-Liquid Chromatography (GLC), the stationary phase is: A high boiling point liquid supported on a solid A finely divided solid adsorbent An inert gas A volatile organic solvent The reaction of sodium nitroprusside with sulfide ions ( S 2- ) in alkaline medium produces a purple-colored ion. The correct formula for this ion is: [Fe(CN) 5NOS] 4- [Fe(CN) 6S] 4- [Fe(CN) 5S] 3- [Fe(CN) 2(S) 4] 2-