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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.
| 101. |
Why is `NH_(4)Cl` essential in the precipitation of group V cations? |
| Answer» Ammonium chloride prevents the precipitation of `Mg^(2+)` as `MgCO_(3)` by the group reagent `(NH_(4))_(2)CO_(3)` by lowering down its dissociation into `NH_(4)^(o+)` and `CO_(3)^(2-)` ions. | |
| 102. |
Why is it essential to oxidise ferrous salt to ferric salt in group III? |
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Answer» This is because the ferrous salts are not compoletely precipitated as `Fe(OH)_(2)` in the presence of `NH_(4)Cl` on the addition of `NH_(4)OH` and thus iron will also be precipitated in the group IV as `FeS` on passing `H_(2)S`. Therefore to precipitate iron completely in the group III, it is necessary to oxidise ferrous salt to ferric salt. |
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| 103. |
Which one has the minimum solubility product ?A. `AgCI`B. `AICI_(3)`C. `BaCI_(2)`D. `NH_(4)CI` |
| Answer» Correct Answer - a | |
| 104. |
Why is it essential to boil off `H_(2)S` gas before proceeding to group III |
| Answer» otherwise the sulphides of group IV will also be precipitated along with precipitate of group III. | |
| 105. |
What can it be, if the precipitate of group I is soluble in hot water and insoluble in cold water? |
| Answer» Correct Answer - `PbCl_(2)` | |
| 106. |
A white metal sulphide soluble in water isA. `CuS`B. `Na_(2)S`C. `PbS`D. `ZnS` |
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Answer» Correct Answer - b Alkali metal salts are water solution |
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| 107. |
Sodium carbonate extract is acidified with `HNO_(3)` only in the identification of halides. Comment. |
| Answer» `HCl` and `H_(2)SO_(4)` are not used, as the acids react with the test reagent `AgNO_(3)` and form ppt. of `AgCl` and `Ag_(2)SO_(4)` respectively because of this only `HNO_(3)` is used for the purpose. | |
| 108. |
Can the solution be acidified with `HNO_(3)` in group II before passing `H_(2)S` gas? |
| Answer» NO, `HNO_(3)` being oxidising in nature oxidises `H_(2)S` gas to form colloidal sulphur which makes the analysis complicated. | |
| 109. |
The compound insoluble in acetic aid isA. calcium oxideB. calcium carbonateC. calcium oxalateD. calcium hydroxide |
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Answer» Correct Answer - c Accetic acid, being an acid reacts with calium oxide, hydroxide and calcium carbonate ,NO reaction with calcuim oxalate. |
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| 110. |
Which of the following sulphate is insoluble in `H_(2)O`A. `CuSO_(4)`B. `PbSO_(4)`C. `CdSO_(4)`D. `Bi(SO_(4))_(3)` |
| Answer» Correct Answer - b | |
| 111. |
Can sodium carbonate extract be used test for `CO_(3)^(2-)` ions ? |
| Answer» No, because it already contains these ions. | |
| 112. |
Which of the following chlodires are water soluble ?A. `AgCI`B. `Hg_(2)CI_(2)`C. `HgCI_(2)`D. `NaCI` |
| Answer» Correct Answer - c,d | |
| 113. |
The sulphide not soluble in hot dilute nitric acid isA. CuSB. ZnSC. CdSD. HgS |
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Answer» Correct Answer - d HgS is insoluble is conc ,`HNO_(2)` it is soluble in aqua regin |
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| 114. |
Which of the following paires can be septated by `H_(2)S` in dil `HCI`?A. `Cu^(2+)` and `Cd^(2+)`B. `Cu^(2+)` and `Ni^(2+)`C. `Cu^(2+)` and `Zn^(2+)`D. `Hg^(2+)` and `Al^(2+)` |
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Answer» Correct Answer - b,c,d Both `Cu^(2+) and Cd^(2+)` are precipitate in group II by `H_(2)S` in dil HCI |
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| 115. |
Which of the following statement is not correct ?A. Lead(II) chloride is soluble in hot water and resppears on coodingB. in dilute HCI th e solubility of `PbCI_(2`) is higher then the hot waterC. in concetrated `HCI,PbCI_(2)` is insolubleD. Lead (II) chloride forms the complex are having white ppt ? |
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Answer» Correct Answer - b,c The solubility of `PbCI_(2)` is already very low in water and is supporessed appreciably in the presence of dil `HCI` `PbCI_(2) + "conc" HCI hArr [PbCI_(2)]^(2)` soluble complax |
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| 116. |
Which of the following is insoluble in dil `HNO_(3)`A. `HgS`B. `PbS`C. `Bi_(2)S_(3)`D. `CuS` |
| Answer» Correct Answer - c | |
| 117. |
Which of the following metal sulphide is soluble in hot and dil `HNO_(3)`?A. `Ag_(2)S`B. `PbS`C. `CdS`D. `HgS` |
| Answer» Correct Answer - a,b,c | |
| 118. |
Which of the following will be completely or parially dissolved in `NH_(4)OH` ?A. `AgCI`B. `AgBr`C. `BaSO_(4)`D. `AgI` |
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Answer» Correct Answer - a,b `AgCI` is completely soluble white `AgBr` is is partially soluble in `NH_(4)OH` |
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| 119. |
Ammonium molybdate is used to test the radicalA. `PO_(4)^(3-)`B. `AsO_(4)^(3-)`C. `Cu^(2+)`D. `Ag^(o+)` |
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Answer» Correct Answer - a,b Both `PO_(4)^(3-) and AsO_(4)^(3-)` give yellow ppt with ammonium molybdate |
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| 120. |
Pick out the correct statement (s):A. Golden yellow `PbI_(2)` dissolves in hot water to give is colourless solutionB. `Ba^(2+) and Ca^(2+)` ions can be sepurated by adding `SO_(4)^(2-)` ion in acetic acid mediumC. Salt of calcium copper and nickel give a green flame colourD. The sulphide ion gives with alkline sodium nitroprtasside ,a violet colour |
| Answer» Correct Answer - a,b,d | |
| 121. |
Potassium cyanide is used for separatingA. `Co^(2+)` and `Ni^(2+)`B. `Cu^(2+)` and `Cd^(2+)`C. `Mn^(2+)` and `Zn^(2+)`D. `Ba^(2+)` and `Ca^(2+)` |
| Answer» Correct Answer - a,b | |
| 122. |
Precipitate of `Na_(2)CO_(3)` extract is made for acid radical analysdis becauseA. All anions react with Na to give water soluble compoundB. Na is more reactiveC. `Na_(2)CO_(3)` is water solubleD. None of the above |
| Answer» Correct Answer - a | |
| 123. |
Which pair would not be expected to form precipitate when solution are mixed?A. `K^(o+),SO_(4)^(2-)`B. `Na^(o+),S^(2-)`C. `Ag^(o+),NO_(3)^(Θ)`D. `Al^(3+),HO^(Θ)` |
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Answer» Correct Answer - a,b,c `AI(OH)_(3)` is insoluble in `H_(2)` |
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| 124. |
Which of the following reacgents can be used to distinguish between `SO_(2)` and `CO_(2)`?A. Lime waterB. Zine nitropruside paste in waterC. Potasium iodate and strachD. Acidfied potessium dichromate of aqueous |
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Answer» Correct Answer - b,c,d Red colour compound of unknown composition is formed when most `SO_(2)` is nrough in cannot with `Zn[Fe(CN)_(5)NO]` (salmon colour ) paste in waetr no colour change with `CO_(2). (c)5SO_(2) +2IO_(2)^(Theta) + 4H_(2)O rarr I_(2)+ 5SO_(4)^(2-) + 8H^(Theta),I_(2) + `stach `rarr` blue colour No colour change observed with `CO_(2)` (d) `3SO_(2) + Cr_(2)O_(7)^(2-) + 2H^(o+) rarr ` `2CI^(3+)` (green solution ) `+3SO_(4)^(2+) + H_(2)O` |
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| 125. |
If `Cu^(2+) and Cd^(2+)` both are present , it is difficult to outline a scheme to analyes in a mixture |
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Answer» `KCN` form comples with `Cu^(2+)` and `Cu^(2+)` `Cu^(2+) + KCN rarr K_(2) underset("Stable")([Cu(CN)_(4)])` `Cd^(2+) + KCN rarr K_(2)underset("Unstable")([Cu(CN)_(4)])` when `H_(2)S` gas pased anstable complex of `Cd^(2+)` given yellow ppt `[Cu(CN)_(4)]^(2) = Cd^(2+) , Cd^(2+) + S^(2-) rarr underset("Yellow") (CdS) darr` |
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| 126. |
Why does a paper soaked in `K_(2)Cr_(2)O_(7)` solution turn green in the detection of `SO_(3)^(2-)` ion? |
| Answer» The paper turns green because the `SO_(2)` gas evolved `SO_(3)^(2-)` salt reduced `K_(2)Cr_(2)O_(7)` to `Cr_(2)(SO_(4))_(3)` which turns the paper green. | |
| 127. |
Which of the following is not precipitate by `H_(2)S` in presence of cone acid solnA. `Cu^(2+)`B. `Al^(3+)`C. `Sb^(3+)`D. `Cd^(2+)` |
| Answer» Correct Answer - b,d | |
| 128. |
When `H_(2)S` gas is passed into aq `ZnCI_(2)` solution white ppt of ZnS is obtained. |
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Answer» Correct Answer - F `ZnCI_(2) +H_(2)S rarr ZnS + 2HCI` ZnS isformed the remain soluble due to formation of HCI ,ZnS is precipitate when `H_(2)S` is passed in ammoniv=cal medium hence false |
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| 129. |
When `Cl_(2)` gas is passed into a mixture containing `Br^(Θ)` and `I^(Θ)` and `CHCI_(3),I_(2)` (voilet ) first appear `CHCI_(3)` layer. |
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Answer» Correct Answer - T Reducing power of `I^(Theta) gt Bi^(Theta) gt CI^(Theta) gt I^(Theta)` `21^(Theta) + CI_(2) rarr 2CI^(Theta) + I_(2)` `2Hi^(Theta) + CI_(2) rarr 2CI^(Theta) + Bi_(2)` Thus `I_(2)` is formed in precipitate of `Bi_(2)` and given violet colour in `CHCI_(2)` hence true |
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| 130. |
`underset("Orange")(Cr_(2)O_(7)^(2-)) underset underset(pH=y)(larr)overset(pH=x)to underset("green")(CrO_(4)^(2-))` The change is based on change uin pH probabole values of x and y can beA. `8,6`B. `8,10`C. `4,6`D. change is independent of pH |
| Answer» Correct Answer - a | |
| 131. |
If `K_(sp)`of `M(OH)_(3)` is `1 xx 10^(-12)` then `0.001 M.M^(2+)` is precipitate in a `pH gt 9` |
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Answer» Correct Answer - T `M(OH)_(3) `is precipitate `[M^(3+)][OH^(Theta)]^(3) gt K_(sp) [OH^(Theta)]^(3)gt 1 xx 10^(-9)` `[OH^(Theta)] gt 1 xx 10^(-3)` Maximum `pOH = 3` Minimum `pH = 9` Hence true. |
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| 132. |
Excess of concentrated sodium hydroxide can separate mixture ofA. `Al^(3+)` and `Cr^(3+)`B. `Cr^(3+)` and `Fe^(3+)`C. `Al^(3+)` and `Zn^(3+)`D. `Zn^(2+)` and `Pb^(2+)` |
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Answer» Correct Answer - b `AI^(2+),Zn^(2+) and Cr^(2+)` form a soluble complex with excess of `NaOH` whereas `Fe^(2+)` does not |
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| 133. |
`H_(2)S` would separate the following in `pH lt 7`A. `Zn^(2+),Co^(2+)`B. `Cu^(2+),Cd^(2+)`C. `Cu^(2+),Cr^(3+)`D. `Cu^(2+),As^(3+)` |
| Answer» Correct Answer - c | |
| 134. |
Concentated aqueous sodium hydroxide cannot separate a mixture ofA. `Al^(3+)` and `Sn^(2+)`B. `Al^(3+)` and `Fe^(3+)`C. `Al^(3+)` and `Zn^(2+)`D. `Zn^(3+)` and `Pb^(2+)` |
| Answer» Correct Answer - a,c,d | |
| 135. |
Select the correct statement(s):A. When `HgCI_(2)` reacts with carbotate ion , then basic mercoury (II) carbonate ion , then `PH` of solution hight increaseB. When `HgCI_(2)` reacts with carbonate ion , Then `pH` of solution highly increasesC. The excess of carbotate acts as buiffer reactys with the hydrogen ions formed in the reaction `CO_(3)^(2-) + 2H^(o+) rarr CO_(2) uarr H_(2)O`D. White ppt of `MgCO_(3) `soble in dil `H_(2)SO_(4)` |
| Answer» Correct Answer - a,c,d | |
| 136. |
Which of the following is (are) soluble in excess of `NaOH`?A. `Cr(OH)_(3)`B. `Fe(OH)_(3)`C. `Al(OH)_(3)`D. `Zn(OH)_(2)` |
| Answer» Correct Answer - c,d | |
| 137. |
`I_(2)` can be obtained from `KI` solution by the action ofA. `CI_(2)`B. `Br_(2)`C. Soluble `CI^(Θ)`D. Solution `Br^(Θ)` |
| Answer» Correct Answer - a,b | |
| 138. |
In group II, Formqation of whichsh tarbidity on dilation with `H_(2)O` indicate `Sb^(3+)` . |
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Answer» Correct Answer - F `SbCI_(3) +H_(2)O rarr underset("Orange")(SbOCI darr) + 2HCI` `BiCI_(3) + H_(2)O rarr underset(white)(BiOCI darr) + 2HCI` White turbidity is due to `BiOCI` (white orange tartbidity is due to `SbOCI)` |
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| 139. |
`NaOH` can be used to seprate `Al(OH)_(3) `and `Zn(OH)_(2)` . |
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Answer» Correct Answer - F `NaOH` can dissolve both `AI(OH)_(2)` and `Zn(OH)_(2)` `AI(OH)_(3) + NaOH rarr NaAIO_(2) `or `Na[AI(OH)_(6)]+ 2H_(2)O` `Zn(OH)_(2) + 2NaOH rarr Na_(2)(Zn(OH)_(4)] or Na_(2)ZnO_(2) + 2H_(2)O` |
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| 140. |
`NH_(4)SCN` can be used to make distanction between `Cu^(2+)` and `Co^(2+)`. |
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Answer» Correct Answer - T `CaCI_(2) + 4NH_(2)SCN rarr underset(Blue colour)((NH_(4))_(2)[Co(SCN)_(4)]) + 2NH_(3)CI` `CuCI_(2) + 2NH_(4)SCN rarr underset(Black ppt)(Cu(SCN)_(2) + 2NH_(4)CI` |
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| 141. |
`NaOH` can be used to seprate `Al(OH)_(3) `and `Zn(OH)_(3)` . |
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Answer» Correct Answer - T `Fe(OH)_(3)` is insoluble while `AI(OH)_(3)` is soluble in `NaOH` forming `NaAIO_(2)` or `Na(AI(OH)_(4)]` hence true |
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| 142. |
Yellow ammonium sulphide (YAS) can be used to seprate SnS and `As_(2)S_(3)`. |
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Answer» Correct Answer - F SnS and `As_(2)S_(3)` both are soluble in YAS hence false |
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| 143. |
Ferric alum is the indicate in the tatration of `Ag^(o+)` with `SCN^(Θ)` when (a)_____colour apears of the end point . |
| Answer» Correct Answer - Red | |
| 144. |
Which of the following salt does give positive test for nitrate ion?A. `KNO_(3)`B. `NaNO_(3)`C. `Mg(NO_(3))_(2)`D. None of these |
| Answer» Correct Answer - a,b,c | |
| 145. |
The correct statement (s) is/are with respect to chromy chloride testA. Formation of lead chromateB. Formation of chromyl chloride chromateC. Liberation of chlorideD. Formation of reddish -brown vapours |
| Answer» Correct Answer - a,b,d | |
| 146. |
A white ppt , is obtainned whenA. A solution of `BaCl_(2)` is treated with `Na_(2)CO_(3)`B. A solution of `CaCl_(2)` is treated with `Na_(2)SO_(3)`C. A solution of `ZnSO_(2)` is treated with `Na_(2)CrO_(4)`D. A solution of `Pb(NO_(3))_(2)`is treated with `Na_(2)CrO_(4)` |
| Answer» Correct Answer - a,b,c | |
| 147. |
A scalet compound A is treated with concenbtrated `HNO_(3)`to gave a chocolate brown precipitate B. The precipitate is filtered and the filtrate is neurralised with NaOH Addition of KI to the resulting solution gives a yellow precipitate C the brown precipitate B on warming with concentrated `HNO_(3) `in the presence of `Mn(NO_(3))_(2)` produces a pink coloured solution due to the formation of D identify A, B,C, and D write the reaction sequence. |
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Answer» A : `Pb_(3)O_(4) B : PbO_(2) C : PbI_(2)O_(4) B : Pb(MnO_(4))_(2)` The pink coloured compound is precipitate salt which is formed by the oxidation of maganese salt lead dioxide .The yellow precipitate to be red lead . `underset((A))(Pb_(3)O_(4)+)4HNO_(3)rarrunderset((B))(PbO_(2)darr)+underset("Filtrate")(2Pb(NO_(3))_(2))+2H_(2)O` `Pb (NO_(3))_(2) +2KI rarr underset("Yellow"(C))(PbI_(2)darr)+2KNO_(3)` `5PbO_(2) +2Mn(NO_(3))_(2) +4HNO_(3) rarr` `Pb(MnO_(4))_(2)+underset((D))(4Pb(NO_(3))_(2))+2H_(2)O` |
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| 148. |
An orange solid A on heating gave qa green residue B, a colourless gas C , and water vapour .The dry gas C on passing over beated Mg gave a white solid D.D on reaction with water gave a gas E formed dense white furmjes with HCI identify A to E and give the reaction involved |
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Answer» The gas E must be ammonia so D is maganessium nitride and gas C is mirogen, It is expected that the orange solid A is ammonium dishromade .The green residue B is `Cr_(2)O_(3) ` `underset((A))((NH_(4))_(2)Cr_(2)O_(7))rarrunderset((B))(Cr_(2)O_(3))+underset((C))(N_(2))+4H_(2)O` `N_(2) +3Mg rarr underset((D))(Mg_(3)N_(2))` `Mg_(3)N_(2)+6H_(2)O rarr 3Mg(OH)_(2) +underset((E))(2NH_(3))` `NH_(3) +HCI rarr NH_(4)CI` (Dense white fumes) |
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| 149. |
An inorganic lewise acid (X) fumes in moist air, and intensity of fumes increases when a red dippole in `NH_(4)OH` is thrugh t near to it .An acidic solution of (X) on addition of `NH_(4)CI` and `NH_(4)OH` gives a percipitate which dissolve in `NaOH` solution .An acidic, solution of (X) does not give precipitate with `H_(2)S` Hence , the compound (X) isA. `FeCI_(3)`B. `AICI_(3)`C. `SnCI_(2)`D. `ZnCI_(2)` |
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Answer» Correct Answer - b `(X)` is `AICI_(3)` `underset("Mostone")(AICI_(3)) + 3H_(2)O rarr AI(OH)_(3) darr + underset(("Fumes"))(3HCI) ` `AICI_(3)+3NH_(4)OH rarr AI(OH)_(3) darr + 3NH_(4)CI` `AI(OH)_(3) + NaOH rarr NaAIO_(2) + 2H_(2)O` `AICI_(3) + H_(2)S + H^(o+) rarr` No ppt |
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| 150. |
Calcium burns in nitrogen to produce a white powder which dissolve in sufficient water to produce a gas A and an alkline solution .The solution on esposure to air produces a this solid layer of B on the surface identify the compound A and B. |
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Answer» A is ammonia and B is calcuim carbonate `Ca+N_(2) rarr underset("White powder")(Ca_(3)N_(2))` `Ca_(#) +H_(2)O rarr Ca(OH)_(2) +underset((A))(NH_(3))` `Ca(OH)_(2) overset(COO_(2))rarr underset((B))(CaCO_(3))+H_(2)O` |
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