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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
(A) is a colourless solid, it metal when heated and gives of a gas (B) Which is supporter of combustion , if heating is contimed the white of the solid disuppears , When (A) is heatyed with an aqueous `NaOH` solution , an alkaline gas (C ) is evolved ,When gas(B) is leasted with sodumine ,a colourless solid (D) is formed .When (D) is heated with dil `H_(2)SO_(4)` a colourless liquid (F) is formed . The mass of compound E isA. AmmoniaB. Hydrazoic acidC. Hydrogen amideD. None of these |
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Answer» Correct Answer - b (A)is `NH_(4)NO_(3)` reactions are i. `underset((A))(NH_(4)NO_(3) underset((B))(N_(2) O) + 2H_(2)O` ii `NH_(4)NO_(3) + NaOH overset(Heat)rarr underset((C))(NH_(3)uarr) +NaNO_(3)+H_(2)O` iii. `underset((B))(N_(2)O)+NaNH_(2) rarr underset("Sodium azide"(D))(NaN_(3))+H_(2)O` `NaN_(3) +H_(2)SO_(4) + underset((E)"hydrazoic acid")(HN_(3))+NaHSO_(4)` `Pb(N_(3))_(2), AgN_(3)` (azides) are expolsive. |
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| 52. |
(A) is a colourless solid, it metal when heated and gives of a gas (B) Which is supporter of combustion , if heating is contimed the white of the solid disuppears , When (A) is heatyed with an aqueous `NaOH` solution , an alkaline gas (C ) is evolved ,When gas(B) is leasted with sodumine ,a colourless solid (D) is formed .When (D) is heated with dil `H_(2)SO_(4)` a colourless liquid (F) is formed . The compound C hasA. Linear geometryB. PyramidalC. TerehedralD. None of these |
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Answer» Correct Answer - b (A)is `NH_(4)NO_(3)` reactions are i. `underset((A))(NH_(4)NO_(3) underset((B))(N_(2) O) + 2H_(2)O` ii `NH_(4)NO_(3) + NaOH overset(Heat)rarr underset((C))(NH_(3)uarr) +NaNO_(3)+H_(2)O` iii. `underset((B))(N_(2)O)+NaNH_(2) rarr underset("Sodium azide"(D))(NaN_(3))+H_(2)O` `NaN_(3) +H_(2)SO_(4) + underset((E)"hydrazoic acid")(HN_(3))+NaHSO_(4)` `Pb(N_(3))_(2), AgN_(3)` (azides) are expolsive. |
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| 53. |
A colourless (A) when place into water a heavy white turbidly of (B) solid (A) gives a close solution in conesolution in cone `HCI` when `HCI` solution is added to clear solution water ,(B) forms again (B) dissolves in dilute `HCI`. When `H_(2)S` is passed through a sespension of (A) or (B), a black precipitate (C ) forms , (C ) is insolves in yellow ammonium sulphide `(NH_(4))_(2)S` , cone `H_(2)SO_(4)` added to solid (A) liberates gas (D) gas (D) is water soluble and gives white precipitate with mercuric salts (E ) and not mercuric salt .The black precipitate (C ) dissolves in `HNO_(3), (1,1)` to give a solution to which `H_(2)SO_(4)` is added followed by addition of `NH_(4)OH` when a white precipitate (F) is formed (E ) gives a black ppt , (G) with solution of sodium stannite. Compound (B ) is not soluble inA. Tartaric ric acidB. HCIC. `HNO_(3)`D. `H_(2)SO_(4)` |
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Answer» Correct Answer - a `underset((A))(BiCI_(3)) +H_(2)O rarr underset("White ppt")(BiOCI darr) +underset((B))(2HCI)` `underset((B))(BiOCI)+2HCI rarr underset((A))(BiCI_(3))+H_(2)O` `2BiCI_(3) + 3H_(2)S rarr underset("Brown-black ppt")(Bi_(2)S_(3)darr) +6HCI` `Bi_(2)S_(3) +8HNO_(3) rarr 2Bi(NO_(3))_(3) +3S darr +2NO +4H_(2)O` `2Bi(NO_(3))_(3) + 3H_(2)SO_(4) rarr Bi_(2) (SO_(4))_(3) +6HNO_(3)` `Bi_(2)(SO_(4))_(3) +6NH_(4)OH rarr underset((F))underset("White ppt") (2Bi(OH)_(3)darr) +3(NH_(4))_(2) SO_(4)` `2Bi(OH)_(3) +3Na_(2)SnO_(2) rarr underset("Black ppt")underset((G))(2Bi) +3Na_(2)SnO_(3) +H_(2)O` `2BiCI_(3) +3H_(2)SO_(4) rarr Bi_(2) (SO_(4))_(3) +underset((D))(6HCI)` `Hg_(2)(NO_(3))_(2) +2HCI rarr underset((E))underset("White ppt")(Hg_(2)CI_(2)darr)+2HNO_(3)` |
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| 54. |
(A) is a colourless solid, it metal when heated and gives of a gas (B) Which is supporter of combustion , if heating is contimed the white of the solid disuppears , When (A) is heatyed with an aqueous `NaOH` solution , an alkaline gas (C ) is evolved ,When gas(B) is leasted with sodumine ,a colourless solid (D) is formed .When (D) is heated with dil `H_(2)SO_(4)` a colourless liquid (F) is formed The compound E hasA. Linear structureB. Bent structureC. Terehedral structureD. None of these |
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Answer» Correct Answer - b (A)is `NH_(4)NO_(3)` reactions are i. `underset((A))(NH_(4)NO_(3) underset((B))(N_(2) O) + 2H_(2)O` ii `NH_(4)NO_(3) + NaOH overset(Heat)rarr underset((C))(NH_(3)uarr) +NaNO_(3)+H_(2)O` iii. `underset((B))(N_(2)O)+NaNH_(2) rarr underset("Sodium azide"(D))(NaN_(3))+H_(2)O` `NaN_(3) +H_(2)SO_(4) + underset((E)"hydrazoic acid")(HN_(3))+NaHSO_(4)` `Pb(N_(3))_(2), AgN_(3)` (azides) are expolsive. |
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| 55. |
`NH_(3)` solution was added to four semple solution in difference test tube and found the following observation about the precipitate. a. White ppt which is solution in oxcess of `NH_(3)` solution b.On heating which is white in cold but yellow on heating c. The cation present in (b) forms white ppt , with hypo solution which give black ppt on heating d. The cation present in (c ) forms soluble complex with excess of `NH_(3)` solution White ppt in (c) and the soluble complex from white ppt with the type solution is//areA. `Pb(OH)_(2),[Pb(S_(2)O_(3))_(2)]^(2)`B. `Ag_(2)O, [Ag(S_(2)O_(3))_(2)]^(2)`C. `HgO.Hg(NH_(2))NO_(3),[Hg(S_(2)O_(3))_(2)]^(2-)`D. None of these |
| Answer» Correct Answer - a,c | |
| 56. |
`NH_(3)` solution was added to four semple solution in difference test tube and found the following observation about the precipitate. a. White ppt which is solution in oxcess of `NH_(3)` solution b. On heating which is white in cold but yellow on heating c. The cation present in (b) forms white ppt , with hypo solution which give black ppt on heating d. The cation present in (c ) forms soluble complex with excess of `NH_(3)` solution The solution initialy present in (a) `+ H_(2)S` (basic medium) gives ppt , then (a) may haveA. `Zn^(2+)`B. `Cd^(2+)`C. `Co^(2+)`D. `Ni^(2+)` |
| Answer» Correct Answer - a,b | |
| 57. |
Cations are classified into varius group on the basis of their behaviour against some reagents .The group reagent used for the classifaction of most common cation are `HCI,H_(2)S,NH_(4)OH,(NH_(4))_(2)CO_(3)`. Classification is based on whether a cation reacts with these reagents by the formation of precipitates or not . Which one among the following paires of ions cannot be separated by `H_(2)S` in the presence of dilute hydrochloric acid ?A. `Bi^(2+),Cd^(2+)`B. `AI^(2+),Hg^(2+)`C. `Zn^(3+),Cu^(2+)`D. `Ni^(2+),Cu^(2+)` |
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Answer» Correct Answer - a Both `Bi^(3+) and Cd^(2+)` will be precipitate in `Bi_(2)S_(3)` (black) and `CdS` (yellow) by `H_(2)S` as both low values of `K_(sp)` than `AI^(3+),Zn^(2+) and Ni^(2+)` (as sulphides) |
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| 58. |
Why is lead plaed in gourp I as well in II? |
| Answer» This is due to fact that lead is not completely precipitated in group I as lead chloride `PbCl_(2)` is also soluble in hot water therefore the lead which escapes precipitation in group I and `PbCl_(2)` is precipitated in the group II as `PbS`. | |
| 59. |
Why are only `Pb^(2+),Ag^(o+)` and `Hg_(2)^(2+)` ions precipitated in group I? |
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Answer» Out of all the chlorides those of `Pb^(2+), Ag^(o+)` and `Hg_(2)^(2+)` are insoluble HCl is the reagent group I. thus chlorides of `Pb^(2+),Ag^(o+)` and `Hg_(2)^(2+)` are precipitated I group I. `AgNO_(3)+Hcltounderset(("white ppt."))(AgCl(s))+HNO_(3)` Other cations remain in solution because their chlorides are soluble. |
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| 60. |
`Na_(2)CO_(3)` cannot be used in place of `(NH_(4))_(2)CO_(3)` for the precipitate of group V becauseA. `Na^(o+)`interferes in the detertion of group VB. Cancentration of `CO_(3)^(2-)` is very lowC. Na will reacts with acid redicalsD. Mg` will be precipitate |
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Answer» Correct Answer - d `Na_(2)CO_(3)` fermishes appreciable `p[CO_(3)^(2-)]` to precipitate `Mg` |
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| 61. |
Which of the following sulphide has the maximum sulubility product ?A. `HgS`B. PbSC. CuSD. MnS |
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Answer» Correct Answer - d The more is `K_(sp) `the higher is soluble .Also in the presence opof `HCI,H_(2)S` gives has `[S^(2-)]` which is sofficient only to cross over the `K_(sp)` of group II sulphide |
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| 62. |
A black sulphide is formed by the action of `H_(2)S` onA. `CaCI_(2)`B. `CdCI_(2)`C. `ZnCI_(2)`D. `NaCI` |
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Answer» Correct Answer - a `CuCI_(2) + H_(2)S rarr underset(("Black"))(CuS)+2HCI` |
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| 63. |
To solution of a salt in acid medium `AgNO_(3)` is added a white ppts repidly changing to yellow orange , brown and finaly is obtained .This isd due to the presence ofA. `SO_(3)^(2-)`B. `S_(2)O_(3)^(2-)`C. `CH_(3)COO^(Theta)`D. `S_(2)^(Theta)` |
| Answer» Correct Answer - b | |
| 64. |
Which of the following is/are connect process for the separation of given ions ?A. `Cu^(2+)` from the mixture of `Cu^(2+)`and `Cd^(2+)` in aqueous solution `Cu^(2+)+ Cd^(2+) overset("Add excess") underset(KCN) to overset("Pass"H_(2)S) underset("and filter") to Cu^(2+)` in the filtrateB. `Cu^(2+)` from the mixture of `Cu^(2+)`and `Cd^(2+)` in aqueous solution `Cu^(2+)+ Cd^(2+) overset("Add excess") underset(KCN) to overset("Pass" H_(2)S) underset("and filter") to Cu^(2+)` in the precipitateC. `Zn^(2+)` from the mixture of `Zn^(2+)`and `Cu^(2+)` in aqueous solution `Zn^(2+)+ Cu^(2+) overset(H_(2)S+dil HCI) to overset("Filter") to Zn^(2+)` in the precipitateD. `Fe^(3+)` from the mixture of `Fe^(2+)`and `Fe^(2+)` in aqueous solution `Fe^(2+)+ Fe^(3+) overset(NH_(4)CI +NH_(3))overset("solution and filter")rarr Fe^(2+)` in the precipitate |
| Answer» Correct Answer - a,b | |
| 65. |
Which of the following cation may be present in white ppt ?A. `Pb^(2+)`B. `Hg^(2+)`C. `Ag^(o+)`D. `Bi^(3+)` |
| Answer» Correct Answer - a,b,c | |
| 66. |
i.(A) `overset(Delta)to ` glassy traparent beat (B) on platinum wire (B) `+ CuSO_(4) rarr ` coloured bead(C ) ii `underset((D))((A))+conc. H_(2)SO_(4)+CH_(3)CH_(2)OH overset("ignite")rarr` green flame iv.Aqueous solution (A) is alkline Identify (B) .A. `NaPO_(3)`B. `NaBO_(2)`C. `NaBO_(2) + B_(2)O_(3)`D. None of these |
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Answer» Correct Answer - c i.(A) Forms glassy transpatent beat which is characteristic property of borax `rArr(A)` is borax `(Na_(2)B_(4)O_(7).10H_(2)O)` `Na_(2)B_(4)O_(3)10H_(2)O overset(Delta) to (NaBO_(2) + B_(2)O_(3))/((B) "Glassy bead") + 10H_(2)O` `B_(2)O_(3) + CuSO_(4) overset(Delta)to underset("Coloured bead(C))(Cu(BO_(2))_(2) +SO_(3)uarr` ii `Na_(2)B_(4)O_(3) + H_(2)SO_(4) + 5H_(2)O rarr NA_(2)SO_(4) + 2H_(3)BO_(3)` `H_(#)BO_(3) +3C_(2)H_(5)OH rarr underset("Green flame" (on ignition")(D))((C_(2)H_(5))_(3)BO_(3)+3H_(2)O)` `Na_(2)B_(4)O_(7)+5H_(2)O rarr underset("Weak acid")(2H_(3)BO_(3))+2Na[B(OH)_(4)]` `Na[B(OH)_(4)]` reacts with acid `(HCI)` hence aqueous solution of (A) is alkaline. |
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| 67. |
Solid `A + H_(2)O rarr (B) `(while turbity which dissolves in HCI) Identify CA. BiOCIB. `Bi_(2)S_(3)`C. `BiCI_(3)`D. `H_(2)S` |
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Answer» Correct Answer - b `underset((A))(BiCl_(3))+H_(2)Oto underset(("Redissolves in HCl"))underset((B))underset("White ppt.")(BiOCldarr)+2HCl` `2BiCl_(3)+3H_(2)Stounderset((C))underset("black ppt.")(Bi_(2)S_(3))+6HCl` `underset((A))(2BiCl_(3))+3H_(2)SO_(4)overset(Delta)toBi_(2)(SO_(4))_(3)+underset((D))(6HCl)` `Hg_(2)(NO_(3))_(2)+2HCl to Hg_(2)Cl_(2) darr +2HNO_(3)` |
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| 68. |
Solid `A + H_(2)O rarr (B) `(while turbity which redissolves in HCI) Identify BA. BiOCIB. `BaS`C. `BaCI_(3)`D. None of these |
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Answer» Correct Answer - a `underset((A))(BiCl_(3))+H_(2)Oto underset(("Redissolves in HCl"))underset((B))underset("White ppt.")(BiOCldarr)+2HCl` `2BiCl_(3)+3H_(2)Stounderset((C))underset("black ppt.")(Bi_(2)S_(3))+6HCl` `underset((A))(2BiCl_(3))+3H_(2)SO_(4)overset(Delta)toBi_(2)(SO_(4))_(3)+underset((D))(6HCl)` `Hg_(2)(NO_(3))_(2)+2HCl to Hg_(2)Cl_(2) darr +2HNO_(3)` |
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| 69. |
Solid `A + H_(2)O rarr (B) `(while turbity which redissolves in HCI) Identify DA. `Br_(2)`B. `HCI`C. `I_(2)`D. `CI_(2)` |
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Answer» Correct Answer - b `underset((A))(BiCl_(3))+H_(2)Oto underset(("Redissolves in HCl"))underset((B))underset("White ppt.")(BiOCldarr)+2HCl` `2BiCl_(3)+3H_(2)Stounderset((C))underset("black ppt.")(Bi_(2)S_(3))+6HCl` `underset((A))(2BiCl_(3))+3H_(2)SO_(4)overset(Delta)toBi_(2)(SO_(4))_(3)+underset((D))(6HCl)` `Hg_(2)(NO_(3))_(2)+2HCl to Hg_(2)Cl_(2) darr +2HNO_(3)` |
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| 70. |
Solid `A + H_(2)O rarr (B) `(while turbity which dissolves in HCI) Identify EA. `Hg_(2)(NO_(3))_(2)`B. `HCI`C. `Hg_(2)CI_(2)`D. `HNO_(3)` |
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Answer» Correct Answer - c `underset((A))(BiCl_(3))+H_(2)Oto underset(("Redissolves in HCl"))underset((B))underset("White ppt.")(BiOCldarr)+2HCl` `2BiCl_(3)+3H_(2)Stounderset((C))underset("black ppt.")(Bi_(2)S_(3))+6HCl` `underset((A))(2BiCl_(3))+3H_(2)SO_(4)overset(Delta)toBi_(2)(SO_(4))_(3)+underset((D))(6HCl)` `Hg_(2)(NO_(3))_(2)+2HCl to Hg_(2)Cl_(2) darr +2HNO_(3)` |
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| 71. |
Identify compound AA. `ZnSO_(4)7H_(2)O`B. `FeSO_(4)7H_(2)SO_(4)`C. `MgSO_(4)7H_(2)O`D. `CuSO_(4)SH_(2)O` |
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Answer» Correct Answer - b (A) is `FeSO_(4).7H_(2)O` `FeSO_(4)+BaCl_(2)tounderset((B))(BaSO_(4)darr)+FeCl_(2)` `2FeSO_(4)overset(Delta)tounderset((E))(Fe_(2)O_(3))+underset((C))(SO_(2))+underset((D))(SO_(3))` `Fe_(2)O_(3)+6HCl tounderset((F))(2FeCl_(3))+3H_(2)O` `2FeCl_(3)+H_(2)Stounderset((H))(2FeCl_(2))+2HCl+underset((G))(S)` `2FeCl_(3)+SnCl_(2)to 2FeCl_(2)+SnCl_(4)` `4FeCl_(3)+3K_(4)Fe(CN)_(6)tounderset("Prussian blue")(Fe_(4)[Fe(CN)_(6)]_(3))+12KCl` |
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| 72. |
Which of the following balides are not soluble in water ?A. `AgCI`B. `AgBr`C. `PbCI_(2)`D. `AgF` |
| Answer» Correct Answer - a,b,c | |
| 73. |
Gases C and D areA. `SO_(2),SO_(3)`B. `SO_(3),CO_(2)`C. `NO_(2),MgO`D. `ZnO,SO_(3)` |
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Answer» Correct Answer - a (A) is `FeSO_(4).7H_(2)O` `FeSO_(4)+BaCl_(2)tounderset((B))(BaSO_(4)darr)+FeCl_(2)` `2FeSO_(4)overset(Delta)tounderset((E))(Fe_(2)O_(3))+underset((C))(SO_(2))+underset((D))(SO_(3))` `Fe_(2)O_(3)+6HCl tounderset((F))(2FeCl_(3))+3H_(2)O` `2FeCl_(3)+H_(2)Stounderset((H))(2FeCl_(2))+2HCl+underset((G))(S)` `2FeCl_(3)+SnCl_(2)to 2FeCl_(2)+SnCl_(4)` `4FeCl_(3)+3K_(4)Fe(CN)_(6)tounderset("Prussian blue")(Fe_(4)[Fe(CN)_(6)]_(3))+12KCl` |
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| 74. |
Identify yellow solution FA. `Fe_(2)O_(3)`B. `FeCI_(2)`C. `ZnCI_(2)`D. `CuCI` |
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Answer» Correct Answer - b (A) is `FeSO_(4).7H_(2)O` `FeSO_(4)+BaCl_(2)tounderset((B))(BaSO_(4)darr)+FeCl_(2)` `2FeSO_(4)overset(Delta)tounderset((E))(Fe_(2)O_(3))+underset((C))(SO_(2))+underset((D))(SO_(3))` `Fe_(2)O_(3)+6HCl tounderset((F))(2FeCl_(3))+3H_(2)O` `2FeCl_(3)+H_(2)Stounderset((H))(2FeCl_(2))+2HCl+underset((G))(S)` `2FeCl_(3)+SnCl_(2)to 2FeCl_(2)+SnCl_(4)` `4FeCl_(3)+3K_(4)Fe(CN)_(6)tounderset("Prussian blue")(Fe_(4)[Fe(CN)_(6)]_(3))+12KCl` |
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| 75. |
Which of the following metal oxide is white in colour but become yellow on heatingA. `AgO`B. `ZnO`C. `Ag_(2)O`D. `FeO` |
| Answer» Correct Answer - b | |
| 76. |
How will you remove the excess of `NH_(4)Cl` before adding `(NH_(4))_(2)CO_(3)` for the precipitation of group? |
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Answer» `NH_(4)Cl` is removed by treating the filtrate from group IV with Conc. `HNO_(3)` on heating to dryness, ammonium chloride is decomposed according to the following equations: `NH_(4)Cl+HNO_(3)toNO_(4)NO_(3)+HCl` `NH_(4)NO_(3)toN_(2)O+2H_(2)O` |
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| 77. |
Even in the absence of group II,colloidal yellowish ppt appears on passing `H_(2)S` gas , it be due to the presence of (a) _____. |
| Answer» Correct Answer - Oxidising agent (like `SO_(3)^(2-),NO_(3)^(Theta))` | |
| 78. |
Which of the following compounds are soluble in water ?A. `CaC_(2)O_(4)`B. `SrSO_(4)`C. `BaCI_(2)`D. `(NH_(4))_(2)C_(2)O_(4)` |
| Answer» Correct Answer - c,d, | |
| 79. |
Which of the following carbonates do not give metal oxide on heating ?A. `CuCO_(3)`B. `K_(2)CO_(3)`C. `Na_(2)CO_(3)`D. `MgCO_(3)` |
| Answer» Correct Answer - b,c, | |
| 80. |
Can we use `NaCO_(3)` in place of `(NH_(4))_(2)CO_(3)` in group V? |
| Answer» No. `(NH_(4))_(2)CO_(3)` is a weak electrolyte and its ionisation is suppressed by the presence of `NH_(4)Cl.Na_(2)CO_(3)` is a strong electrolyte and in its solution `[CO_(3)^(2-)]` is pretty high to precipitate even `MgCO_(3)` in the group. V. | |
| 81. |
Find the number of reducing agents from the following `H_(2)S,SO_(3),CrO_(4)^(2-),Fe^(2+),MnO_(4)^(Θ)` |
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Answer» Correct Answer - 2 `H_(2)S,Fe^(2-)` |
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| 82. |
Find the number of ion which are identified by dil. HCI from the following : (i) `CO_(3)^(2-) `(ii) `SO_(3)^(2-)` (iii)`SO_(4)^(2-)` |
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Answer» Correct Answer - 2 `CO_(3)^(2-) `and `Fe^(2-)` |
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| 83. |
Select the correct statement(s):A. `NaHCO_(2)` is sparingly soluble in water because ithas massive H-bondingB. When `BaCI_(2)` reacts with bicarbonatie, then white ppt of `BaCO_(3)` is formedC. `HgCI_(2)` is poisonousD. Phenophthelein is turned pink by soluble carbonate and colourless by soluble hydrogen carbonate. |
| Answer» Correct Answer - a,c,d | |
| 84. |
Select the correct statement(s):A. White ppt of `BaSO_(3)` and `CaSO_(4)` is soluble in dil `HNO_(3)` dil `HCI` and `CH_(3)COOH`B. On standing the precipitate `BaSO_(4)` is slowly oxidised to salphte and then becomes insolable in dilute mineral acidC. When excess of `SO_(2)` gas is passed into the solution of `BaSO_(3)` and `CaSO_(3) ` then white turbility disappeareD. The hydrogen carbonate of alkali metals are soluble in water , but are less soluble then the cprresponding normal carbotates |
| Answer» Correct Answer - b,c,d | |
| 85. |
Which of the following compound are having white ppt ?A. `K_(2)Fe[Fe(CN)_(6)]`B. `[Fe(H_(2)O)_(3)(SCN_(1))]^(2+)`C. `ZnS`D. `Zn(OH)_(2)` |
| Answer» Correct Answer - a,c,d | |
| 86. |
Which of the following is/are correct for potassium ferrcysnide?A. it gives a brown precipitate with `Cu^(2+)` ionsB. it gives a red precipitate of mixed salt `Cd^(2+)` ionsC. If in excess gives a white precipitate with `Zn^(2+)`D. It develops a deep red coloured with `Fe^(3+)` |
| Answer» Correct Answer - a,c | |
| 87. |
Why does only the organic layer assure colour and not the aqueous layer when the tests for halides are done? |
| Answer» Both `Br_(2)` and `I_(2)` are covalent. They have preference for organic layer. | |
| 88. |
`S^(2-) and SO_(3)^(2-)` can be distinguished by usingA. `(CH_(2)COO)_(2)Pb`B. `Na_(2)[Fe(CN)_(5)NO]`C. `CO_(2)O_(7)^(2-)` solutionD. `CaCI_(2)` |
| Answer» Correct Answer - a,b,d | |
| 89. |
Interfering radicals interfere the test ofA. Group III radicals onlyB. Group III radicals or downwardC. Cation which are present in group II fitrateD. None of these |
| Answer» Correct Answer - b,c | |
| 90. |
`AlCl_(2)` is soluble is axcess of `NaOH` forming sodium metaaluminate `Na[Al(OH)_(4)]`. |
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Answer» Correct Answer - T `AICI_(3) + NaOH rarr 3NaCI + AI(OH)_(3) darr` `AI(OH)_(3) + NaOH rarr underset("Soluble")(Na[AI(OH)_(4)])` Hence true. |
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| 91. |
An aqqeous solution of a substance gives a white precipitate on tretment with diute hydrocloric acid which which dissolves on heating .When hydrogen sulphide is passed through the hot acidic solution a black precipitate is obtained .The substance is aA. `Hg_(2)^(2+)` saltB. `Cr^(+)` saltC. `Ag^(o+)` saltD. `Pb^(2+)`salt |
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Answer» Correct Answer - d A white precipitate which is soluble in hot water is lead chloride `Pb^(2+) + 2HCI rarr underset(white)(PbCI_(2) darr ) + 2H^(oplus)` `underset(Hot solution)(PbCI_(2))+H_(2)S overset(H^(o+))rarr overset(White)underset(Black)(PbSdarr) +2HCI` |
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| 92. |
Does the excess of `NH_(4)Cl` affect the precipitation of group V cations by `(NH_(4))_(2)CO_(3)?` |
| Answer» Yes, the concentration of `CO_(3)^(2-)` is decreased because the common ion `NH_(4)^(o+)` suppresses the ionisation of `(NH_(4))_(2)CO_(3)`. | |
| 93. |
The reagents `NH_(4)Cl` and `NH_(3)` will precipitate :A. `Ca^(2+)`B. `Al^(2+)`C. `Bi^(2+)`D. `Mg^(2+)` |
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Answer» Correct Answer - b,c `AI^(3+)` and `Br^(3+)` are precipitate as their hydroxides `[AI(OH)_(3),Bi(OH)_(3)]` with ammonium hydroxide in the presence of ammonium chloride |
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| 94. |
Why sometimes colloidal precipitate is obtained in group IV? Comment |
| Answer» to prevent the colloidal precipitate ammonium chloride must be present in large amount `H_(2)S` should not be passed must be present in large amount `H_(2)S` should not be passed for long. | |
| 95. |
Why sometimes, a black coloured precipitate obtained in group IV even if nickel and cobalt ions are absent? |
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Answer» A blakc coloured precipitate is obtained the group IV due to the incomplete removal of iron in group III. Iron escapes precipitation in group III due to lack of enough `NH_(4)OH.Fe^(+3)` is reduced to `Fe^(2+)` by `H_(2)S` which finally gets precipitated as FeS (black) in group IV even when both Co and Ni are absent. `FeCl_(2)+H_(2)Sto2HCl+underset(("Black ppt"))(FeS(s))` |
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| 96. |
Why is only acetic acid employed for dissolving the group V ppt. |
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Answer» it is due to the following reasons: a. if `H_(2)SO_(4)` is used `Ba^(2+),Sr^(2+)` and `Ca^(2+)` will be precipitated as their sulphates. b. if the ppt. is dissolved either in dilute HCl or in dil. `HNO_(3)` calcium will not be precipitated by adding `(NH_(4))_(2)C_(2)O_(4)` because `CaC_(2)O_(4)` formed in soluble in both dil. HCl and di. `HNO_(3)` however, the use of `CH_(3)COOH` is free from the above difficulties, hence it is used for dissolving the group V precipitates. |
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| 97. |
Identify the correct order solubility in apocous mediumA. `Na_(2)S gt CuS gt ZnS`B. `Na_(2)S gt ZuS gt CuS`C. `ZnS gt Na_(2)S gt CuS `D. `Na_(2)S gt CuS gt ZnS` |
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Answer» Correct Answer - b,c Higher the `K_(sp)` of sulphides more is the solubility in aqueous medium In the salt analysis `K_(sp)` sulphides increases from group `1` of salt anlysis to group `IV` of salt anlysis `Cu^(+2)` ion is in group II whereas `Zn^(+2)` is in group IV of salt analysis `:.` Solubility of `ZnS gt CuS` since the `K_(sp)` of sulphides of sodium is the bighest therefore it is highly soluble Hence the answer is (b) i.e. solubility of `Na_(2)S gt ZnS CuS` |
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| 98. |
An aqueous solution of a mixture of two inorganic salt , when reated with diute HCI ,Gave a precipitate (P) and a filrate (Q) .The precipitate P was found to dissolve in hot water .The filrate (Q) remained unchanged , white tracated with `H_(2)S` in a difute mineral acid medium .However it gave a precipitate (R ) with `H_(2)S` in an ammoniacal medium .THe precipitate R give a coloured solution (S ) when treated with `H_(2)O_(2)` to an aq2ueous `NaOH` medium The coloured solution S containA. `Fe_(2)(SO_(4))_(3)`B. `CuSO_(4)`C. `ZnSO_(4)`D. `Na_(2)CrO_(4)` |
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Answer» Correct Answer - d The precipitate `(P)` contains `Pb^(2+)` `Pb^(2+) + 2HCI rarr PbCI^(2+) overset(Hot) underset(water)(to) Solution` The filtrate `(Q)` contains `Cr^(+3)`, since it does give any precipitate with `H_(2)S` in acide medium .But gives precipitate`(R )` with `H_(2)S` in alkline medium So, `R` is `Cr(OH)_(3)` and S is `Na_(2)CrO` `Cr^(+3) overset(Ammonical) underset(H_(2)S)to Cr(OH)_(3) overset(H_(2)O_(3))underset(NaOH)to underset(yellow soln)(Na_(2)CrO_(4))` |
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| 99. |
Why is `H_(2)SO_(4)` never employed for preparing original solution for the identification of cations? |
| Answer» `Ba^(2+),Sr^(2+)` and `Pb^(2+)` ar precipitated as insoluble sulphates. | |
| 100. |
Which of the following ppt is insoluble in `NH_(3)` solution ?A. `AgI`B. `Ag_(2)S`C. `AgCl`D. `AgBr` |
| Answer» Correct Answer - a,b | |