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151.

Can we use `Ba(NO_(3))_(2)` instead of `BaCl_(2)` for testing sulphate radical?

Answer» Yes, infact we need `Ba^(2+)` to precipitate out the `SO_(4)^(2-)` as `BaSO_(4)`.
Discussion
152.

Mercuric nitrate solution reacts with a soluble sulphate forming a yellow precipitate. If the statement is true then explain giving the complete balanced equation.

Answer» `SO_(4)^(2-)+3 Hg^(2+)+2H_(2)OtoHgSO_(4).2HgO darr +4H^(+)`
Yellow precipitate is owing to the formation of basic `Hg(II)` sulphate.
Discussion
153.

Which of the following combination in aqueous medium will give a red colour or precipitate ?A. `Fe^(3+)+SCN^(-)`B. `Fe^(2+)+[Fe(CN)_(6)]^(3-)`C. `Ni^(2+)+` dimethyl glyoxime `+NH_(3)`D. `CO^(2+)+SCN^(-1)`

Answer» Correct Answer - A,C
Discussion
154.

In which of the following cases will a violet coloration be observed ?A. An alkaline solution sodium nitroprusside is treated with a solution of `Na_(2)S`.B. A solution of sodium cobaltinitrite is treated with one of KCl.C. A solution of `Mn(N_(3))_(2)` is treated with sodium bismuthate or red lead in presence of concentrated `HNO_(3)`D. A solution of sodium nitroprusside in aqueous NaOH is treated with `Na_(2)SO_(2)O_(3)`.

Answer» Correct Answer - A,C
Discussion
155.

Barium sulphate on fusion charcoal and sodium carbonate yields a compound `(X).(X)` on reaction with dilute HCl liberates a gas `(Y)`. The gas `(Y)` can be identified by `:`A. blackening of filter paper moistened with lead acetate solution.B. turning the filter paper yellow moistened with cadmium acetate solution.C. turning the filter paper purple moistened with sodium nitroprusside made alkaline with ammonia solutionD. all of these

Answer» Correct Answer - 4
Discussion
156.

Statement-1 :Acidified `K_(2)Cr_(2)O_(7)` solution becomes green when `SO_(2)` gas is passed through it. Statement-2 :This is an redox reaction.A. STATEMENT-1 is true, STATEMENT-2 is true and STATEMENT-2 is correct explanation for STATEMENT-1B. STATEMENT-1 is true, STATEMENT-2 is true and STATEMENT-2 is not correct explanation for STATEMENT-2C. STATEMENT-1 is true, STATEMENT-2 is falseD. STATEMENT-1 is false, STATEMENT-2 is true

Answer» Correct Answer - B
Discussion
157.

Zinc pieces are added to acidified solution of `SO_(3)^(2-)`.Gas liberated can:A. turn lead acetane paper blackB. turn lime water milkyC. give white precipitate with `AgNO_(3)` solutionD. decolourize acidified `KMnO_(4)`

Answer» Correct Answer - A,D
`SO_(3)^(2-)+Zn+8H^(+)toH_(2)Suarr+3Zn^(2+)+3H_(2)O`
`Pb^(2+)+S^(2-)toPbSdarr`(black)
`Ag^(+)+S^(2-)toAg_(2)Sdarr` (black)
`2MnO_(4)^(-)+5H_(2)S+6H^(+)to2Mn^(2+)+5S+8H_(2)O`
Discussion
158.

Black precipitate of copper sulphide dissolves in:A. `KCN` solutionB. sodium sulphide solutionC. sodium hydroxideD. boiling dilute `(M)` sulphuric acid.

Answer» Correct Answer - A
Discussion
159.

An orange precipitate in the second group is given byA. `Sn^(2+)`B. `Sb^(3+)`C. `Hg^(2+)`D. `As^(3+)`

Answer» Correct Answer - B
`Sb^(3+)` with `H_(2)S` in presence of dil. HCl gives `Sb_(2)S_(3)` ( orange ppt)
while `Hg^(2+)` gives HgS (black ppt)
`As^(3+)` gives `As_(2)S_(3)`(yellow ppt)
`Sn^(2+)` gives SnS ( brown ppt)
Discussion
160.

`Mg` is not precipitated in `V` group because:A. `MgCO_(3)` is soluble in water.B. `K_(sp)` of `MgCO_(3)` is high.C. `MgCO_(3)` is soluble in `NH_(4)OH`D. None

Answer» Correct Answer - B
Discussion
161.

Statement-1:Baryta water becomes turbid on passing `CO_(2)` gas through it but turbidity becomes clear on passing more `CO_(2)` gas. Statement-2 : Carbonates give yellowish white precipitate with silver nitrate solution.The precipitate becomes yelllow or brown on heating.A. STATEMENT-1 is true, STATEMENT-2 is true and STATEMENT-2 is correct explanation for STATEMENT-1B. STATEMENT-1 is true, STATEMENT-2 is true and STATEMENT-2 is not correct explanation for STATEMENT-2C. STATEMENT-1 is true, STATEMENT-2 is falseD. STATEMENT-1 is false, STATEMENT-2 is true

Answer» Correct Answer - B
Statement-1:`Ba(OH)_(2)+CO_(2)toBaCO_(3)darr (white) +H_(2)O, BaCO_(3) + H_(2)O+CO_(2) to Ba(HCO_(3))_(2)`
Statement-2:`2Ag^(+) + CO_(3)^(2-) to Ag_(2)CO_(3) darr ("white"),Ag_(2)CO_(3) darr overset(Delta) to Ag_(2)O darr ("brown") +CO_(2) uarr`
Discussion
162.

A substance on treatment with dilute `H_(2)SO_(4)` liberates a colourless gas which produces `(I)` turbidity with baryta water and `(ii)` turns acidified dichromate solution green. The reaction indicates the presence of `:`A. `CO_(3)j^(2-)`B. `S^(2-)`C. `SO_(3)^(2-)`D. `NO_(2)^(-)`

Answer» Correct Answer - C
`Na_(2)SO_(3)+2HCl("dil.")rarrNaCl+H_(2)O+SO_(2)`
`K_(2)Cr_(2)O_(7)+H_(2)SO_(4)+3SO_(2)rarrK_(2)SO_(4)+Cr_(2)(SO_(4))_(3)+H_(2)O`
Discussion
163.

Nitrates is confirmed by ring test.The brown colour of the ring is due to formation of:A. ferrous nitriteB. nitroso ferrous sulphateC. ferrous nitrateD. `FeSO_(4).NO_(2)`

Answer» Correct Answer - B
`2NO_(3)^(-)+4H_(2)SO_(4)+6Fe^(2+)to6Fe^(3+)+2NOuarr+4SO_(4)^(2-)+4H_(2)O`
`Fe^(2+)+NOuarr +SO_(4)^(2-) to [Fe(NO)]^(2+)SO_(4)^(2-)`
Discussion
164.

In the brown ring test, the brown colour of the ring is due toA. a mixture of NO and `NO_(2)`B. nitrosoferrous sulphateC. ferrous nitrateD. ferric nitrate

Answer» Correct Answer - 2
`underset("Brown ring")([Fe(H_(2)O)_(5)NO]SO_(4))`
Discussion
165.

`Ni+H_(2)SO_(4)` (hot and concentrated) `to X(g)` The liberated gas (select the correct statement)A. develops blue colour spots on the filter paper moistened with potassium iodate and strach solutionB. turns acidified `K_(2)Cr_(2)O_(7)` solution greenC. produces black precipitate with lead acetate solutionD. reacts with `Cl_(2)` water to produce an acid which gives white fumes with ammonia.

Answer» Correct Answer - A,B,D
(A)`5SO_(2)+2IO_(3)^(-)+4H_(2)O to I_(2)+5SO_(4)^(2-)+8H^(+) , I_(2)+` starch `to` blue colour.
(B)`2H^(+)+3SO_(2)+Cr_(2)O_(7)^(2-) to 2Cr^(3+) ("green")+3SO_(4)^(2-) +H_(2)O`
( C)`Pb^(2+)+SO_(3)^(2-) to PbSO_(3) darr `(white)
(D)`SO_(2)+2H_(2)O +CI_(2) to H_(2)SO_(4) + HCl`
`HCl+NH_(3) to NH_(4)Cl`
`NI+H_(2)SO_(4) +2H^(+) to Ni^(2+) +SO_(2) uarr [X] + 2H_(2)O`
With dilute `H_(2)SO_(4)`, hydrogen gas is liberated.
Discussion
166.

Magnesium is precipitated from its salt solution as only magnesium ammonium phosphate by adding disodium hydrogen phosphate solution in absence of ammonium chloride and aqueous ammonia.

Answer» Precipitation is carried out in presence of ammonium chloride and aqueous ammonia as they prevent precipitation of magnesium hydroxide.
`Mg^(2+)+NH_(3)+HPO_(4)^(2-)toMg(NH_(4))PO_(4)darr`(white)
Discussion
167.

In salt analysis cations of group I and II precipitated in acidic medium and therefore the solution remains acidic till group II. But from III group onwards cations precipitates in basic medium and hence filtrate of group II is to be boiled with con `HNO_(3)` before using it for III group. The use of `Br_(2)` and NaOH to group III precipitate facilitatesA. rendering Al into sodium meta-aluminateB. rendering Fe into `Fe(OH)_(2)`C. conversion of Cr into soluble sodium chromateD. removal of group III ions before starting group IV

Answer» Correct Answer - C
`Cr^(3+)` makes soluble sodium chromate in presence of `Br_(2)//NaOH` to allow precipitation.
Discussion
168.

To increase significantly the concentration of free `Zn^(2+)` ion is a solution of the complex ion `[Zn(NH_(3))_(4)]^(2+)` `Zn^(2+) (aq)+4NH_(3) (aq) hArr [Zn(NH_(3))_(4)]^(2+) (aq)` Add to the solution some:A. `H_(2)O`B. `HCl(aq)`C. `NH_(3)(aq)`D. `NH_(4)Cl(aq)`

Answer» Correct Answer - B
Discussion
169.

Which of the following gives a precipitate with `Pb(NO_(3))_(2)`?A. Sodium chlorideB. Sodium acetateC. Sodium nitrateD. Disodium hydrogen phosphate

Answer» Correct Answer - A
(A)`Pb^(2+)+2Cl^(-)rarrPbCl_(2)darr`(white), `Ba^(2+)+2Cl^(-) to BaCl_(2)` (water soluble)
(B)`(CH_(3)COO)_(2) Pb` and `(CH_(3)COO)_(2)Ba` both are water soluble salts.
( C)Nitrates are mostly soluble in water
(D)`3Pb^(2+)+2HPO_(4)^(2-)rarr Pb_(3)(PO_(4))_(2)darr`(white)+`2H^(+),Ba^(2+)+HPO_(4)^(2-)toBaHPO_(4)darr`(white)
Discussion
170.

A blue colouration is not obtained whenA. ammonium hydroxide dissolves in copper sulphate.B. Copper sulphate solution reacts with `K_(4)[Fe(CN)_(6)]`.C. Ferric chloride reacts with sodium ferrocyanide.D. anhydrous white `CuSO_(4)` is dissolved in water.

Answer» Correct Answer - 2
Discussion
171.

Colour of cobalt chloride solution is:A. pinkB. blackC. colourlessD. green

Answer» Correct Answer - A
Anhydrous Co`(II)` salts are blue in colour white hydrated Co`(II)` salts are pink/red.
Discussion
172.

A red colouration or precipitate is not obtained when:A. `Fe^(3+)` reacts with potassium thiocyanateB. `Fe^(2+)` reacts with dimethylglyoxime.C. `Hg^(2+)` reacts with potassium iodide.D. None

Answer» Correct Answer - D
(A)`Fe^(3+)+3SCN^(-)toFe(SCN)_(3)`(red solution)
(B)Red solution of iron `(II)` dimethylglyoxime.
(C )`Hg^(2-)+2l^(-)toHgl_(2) darr` (red).
Discussion
173.

The aqueous solution of which salt is coloured ?A. `Zr(NO_(3))_(2)`B. `LiNO_(3)`C. `Co(NO_(3))_(2)`D. Potash alum

Answer» Correct Answer - C
Discussion
174.

`Sb_(2)S_(3)` is -A. BlackB. YellowC. OrangeD. None

Answer» Correct Answer - 3
Discussion
175.

Which is soluble in `NH_(4)OH` ?A. `PbCl_(2)`B. `AgCl`C. `PbSO_(4)`D. `CaCO_(3)`

Answer» Correct Answer - 2
Discussion
176.

The aqueous solution of which salt is colouredA. `Zn(NO_(3))_(2)`B. `LiNO_(3)`C. `Co(NO_(3))_(2)`D. Potash alum

Answer» Correct Answer - 3
Discussion
177.

Which of the sulphide is yellow-A. ZnSB. CdSC. NiSD. PbS

Answer» Correct Answer - 2
Discussion
178.

A black sulphide is formed by the action of `H_(2)S` on:A. cupric chlorideB. cadmium chlorideC. zinc chlorideD. ferric chloride

Answer» Correct Answer - A
(A)`Cu^(2+) + S^(2-) to CuS darr`(black),
(B)`Cd^(2) + S^(2-) to CdS darr` (yellow)
( C)`Zn^(2+)+S^(2-) to ZnS darr` (white)
(D)`2Fe^(3+) + H_(2)S to 2Fe^(2+)+2H^(+) +S darr`(milky white)
Discussion
179.

`Cu^(2+)` ions will be reduced to `Cu^(+)` ions by the addition of an aqueous solution of:A. `Kl`B. `KCl`C. `KSCN`D. `KCN`

Answer» Correct Answer - A,C,D
`2CuSO_(4)+4Kl to 2"Cul" darr("white")+2K_(2)SO_(4)+l_(2)`
`3SCN^(-)+Cu^(2+) to CuSCN darr ("white")+(SCN)_(2)`
`6CN^(-)+Cu^(2+) to [Cu(CN)_(4)]^(3-)+(CN)_(2)`
Discussion
180.

Which of the following statement is incorrect.A. `Cu^(2+)` on reaction with `K_(4)[Fe(CN)_(6)]` gives a chocolate brown ppt.B. `Fe^(3+)` on reaction with `K_(4)[Fe(CN)_(6)]` gives a blue ppt.C. `Ag^(+)` on reaction with `K_(4)[Fe(CN)_(6)]` gives a orange ppt.D. Potassium hexacyanoferrate (II) complex is diamagnetic.

Answer» Correct Answer - C
Discussion
181.

Salt`(A)` on heating gives a colourless neutral gas which supports combustion. From the aforesaid, flow diagram, answer the following questions. Which of the following statement is correct ?A. Salt `(A)` gives yellow precipitate with chloroplatinic acid as well as with sodium cobaltinitrite.B. The brown ring is formed due to the formation of nitroso ferrous sulphate `[Fe(NO)]^(2+)SO_(4)^(-)`.C. Salt `C` reacts with silver nitrate solution to form white precipitate.D. (A) and (B) both.

Answer» Correct Answer - D
(A)`2NH_(4)^(+)+[PtCl_(6)]^(4-)to(NH_(4))_(2)[PtCl_(6)]darr`(yellow)
`3NH_(4)^(+)+[Co(NO_(2))]^(3-)to(NH_(4))_(3)[Co(NO_(2))_(6)]darr`(yellow)
(B)`2NO_(3)^(-)+4H_(2)SO_(4)+6Fe^(3+)+2NO uarr+4SO_(4)^(2-)+4H_(2)O`
`SO_(4)^(2-)+Fe^(2+)+NOto[Fe(NO)]^(2+)SO_(4)^(2-)`
( C)`Ag NO_(3)+NaNO_(3)to`No reaction.
If the anion is `NO_(2)^(-)` then `Ag^(+)+NO_(2)^(-)toAg NO_(2)darr`(white)
Reactions:
`underset((A))(NH_(4)NO_(3))+NaOH to underset((B))(NH_(3)uarr)+underset((C))(NaNO_(3))`
`NH_(3)+HCl to NH_(4)Cluarr`(White)
`NO_(3)^(-)+4Zn+7OH^(-)+6H_(2)O to NH_(3)+4[Zn(OH)_(4)]^(2-)`
Discussion
182.

What happens when ? (A) Aqueous solution of `CrCl_(3)` is added to ammonia solution. (B) Ammonium carbonates reacts with `MgCl_(2)` (i) in absence of ammonium salts and (ii) in presence of ammonium salts:

Answer» (A)`Cr^(3+)+3NH_(3)+3H_(2)OtoCr(OH)_(3)darr` (green)+`3NH_(4)^(+)`
`Cr(OH)_(3)` precipitate formed becomes slightly soluble in excess of precipitant in cold forming a violet or pink solution containing `[Cr(NH_(3))_(6)]^(3+)` complex ions.
`Cr(OH)_(3)darr+6 NH_(3)to[Cr(NH_(3))_(6)]^(3+)+3OH^(-)`
(B)(i)`5Mg^(2+)+6CO_(3)^(2-)+7H_(2)Oto4MgCO_(3).Mg(OH)_(2).5H_(2)Odarr+2HCO_(3)^(-)`
White precipitate of basic magnesium carbonate is formed.
(ii)In presence of ammonium salts no precipitation occurs, because the equilibrium
`NH_(4)^(+)+CO_(3)^(2-)toNH_(3)+HCO_(3)^(-)` is shifted towards the formation of `HCO_(3)^(-)` ions.
Discussion
183.

Give two examples of acid radicals detected with dilute `H_(2)SO_(4)`.

Answer» `CO_(3)^(2-),S^(2-),SO_(3)^(2-),NO_(2)^(-),CH_(3)COO^(-)`
Discussion
184.

Give two examples of acid radicals detected with concentrated `H_(2)SO_(4)`.

Answer» `Cl^(-),Br^(-),I_(-)NO_(3)^(-)`
Discussion
185.

Why do lead salts turn black on keeping for a long time in the laboratory?

Answer» `Pb^(2+)+H_(2)S ("atmospheric")toPbS darr("black")+2H^(+)`.
Discussion
186.

Why a salt containing lead turns black in colour, when placed for a long time in laboratory?

Answer» Due to the formation of black lead-sulphide by the action of `H_(2)S` in atmosphere.
Discussion
187.

Which acidic radical of dil. `H_(2)SO_(4)` group gives brown ring test?

Answer» Correct Answer - `NO_(2)^(-)`
Discussion
188.

An aqueous solution of salt gives salt precipitate with `AgNO_(3)` solution as well as with dilute `H_(2)SO_(4)`. It may beA. `Pb(NO_(3))_(2)`B. `Ba(NO_(3))_(2)`C. `BaCl_(2)`D. `CuCl_(2)`

Answer» Correct Answer - C
`BaCl_(2)+2AgNO_(3) to 2AgCl darr("white")+BaNO_(3)`
`BaCl_(2)+H_(2)SO_(4) to BaSO_(4) darr ("white") + 2HCl`
Discussion
189.

The addition of `K_(2)CO_(3) (aq)` to the following solution is expected to produce a precipitate in every case but that one which does not produce precipitate is:A. `BaCl_(2) (aq)`B. `CaCr_(2) (aq)`C. `Na_(2)SO_(4) (aq)`D. `Pb(NO_(3))_(2)(aq)`

Answer» Correct Answer - C
Discussion
190.

The acidic solution of a salt produced a deep blue colour with starch iodine solution. The salt may beA. SuphiteB. BromideC. NitriteD. Chloride

Answer» Correct Answer - C
Discussion
191.

`NO_(2)` turns acidic `KI`-starch paper blue, why?

Answer» `NO_(2)` turns `I^(-)` into `l_(2)`, which gives dark blue complex with starch.
`2Kl+H_(2)SO_(4)+NO_(2)toK_(2)SO_(4)+H_(2)O+NO+I_(2)`
Discussion
192.

There is formation of blue colour when `(KI+` Starch ) is added toA. `HNO_(2)`B. `CuSO_(4)`C. `Cl_(2)`D. `Cr_(2)O_(7)^(-2)//H^(+)`

Answer» Correct Answer - A,B,C,D
All will oxidise KI to `I_(2)`.
Discussion
193.

Which of the following pairs of ions would be expected to form precipitate when dilute solution are mixed ?A. `Na^(+),SO_(4)^(2-)`B. `NH_(4)^(+),CO_(3)^(2-)`C. `Na^(+),S_(2)^(2-)`D. `Fe^(3+),PO_(4)^(3-)`

Answer» Correct Answer - 2
Discussion
194.

The pair (s) of ions where both the ions are precipitate upon passing `H_(2)S` gas in presence of dilute `HCl`, is (are)A. `Ba^(2+), Zn^(2+)`B. `Bi^(3+), Fe^(3+)`C. `Cu^(2+), Pb^(2+)`D. `Hg^(2+), Bi^(3+)`

Answer» Correct Answer - C::D
Discussion
195.

Which of the following pair (s) of ions would be expected to form precipitate when dilute solutions are mixed?A. `NH_(4)^(+),[Co(NO_(2))_(6)]^(3-)`B. `NH_(4)^(+),CO_(3)^(2-)`C. `Fe^(3+),OH^(-)`D. `Ba^(2+),SO_(4)^(2-)`

Answer» Correct Answer - A,C,D
(A)`NH_(4)^(+)+[Co(NO_(2))_(6)]^(3-)to(NH_(4))_(3)[Co(NO_(2))_(6)]darr`(yellow)
(B)Ammonium and alkali metal carbonates are water soluble.
( C)`Fe^(3+)+OH^(-)toFe(OH)_(3)darr`(reddish-brown)
(D)`Ba^(2+)+SO_(4)^(2-)toBaSO_(4)darr` (white)
Discussion
196.

Colourless salt (A) on heating with NaOH gives gas (B). When reaction of (A) with NaOH was complete, solution obtained on reacting `FeSO_(4)` and conc. `H_(2)SO_(4)` gave a brown coloured ring (C ) between two layers. (A) on heating strongly forms (D ) and (E). Compound (E ) is neutral oxide of a dibasic acid (F). Compound (F) isA. `H_(2)NO_(2)`B. cis `H_(2)N_(2)O_(2)`C. trans `H_(2)N_(2)O_(2)`D. both (B) and (C )

Answer» Correct Answer - D
`underset((A))(NH_(4)NO_(3))+NaOHoverset(Delta)(rarr)underset((B))(NH_(3))+NaNO_(3)+H_(2)O`
`NO_(3)^(-)+FeSO_(4)+H_(2)SO_(4)rarrunderset("Brown ring ")([Fe(H_(2)O)_(5)NO]SO_(4))`
`underset((F))(HO)-overset(ddot)(N)=overset(ddot)(N)-OHoverset(Delta)(rarr)N_(2)O+underset((E))(H_(2)O)`
`underset((A))(NH_(4)NO_(3))" "underset((D))(N_(2)O)+underset((E))(2H_(2)O)`
Discussion
197.

Colourless salt (A) on heating with NaOH gives gas (B). When reaction of (A) with NaOH was complete, solution obtained on reacting `FeSO_(4)` and conc. `H_(2)SO_(4)` gave a brown coloured ring (C ) between two layers. (A) on heating strongly forms (D ) and (E). Compound (E ) is neutral oxide of a dibasic acid (F). What is the compound (C)A. `[Fe(H_(2)O)_(4).NO]SO_(4)`B. `[Fe(H_(2)O)_(5)NO]SO_(4)`C. `[Fe(H_(2)O)_(4)]SO_(4)`D. None of these

Answer» Correct Answer - B
`underset((A))(NH_(4)NO_(3))+NaOHoverset(Delta)(rarr)underset((B))(NH_(3))+NaNO_(3)+H_(2)O`
`NO_(3)^(-)+FeSO_(4)+H_(2)SO_(4)rarrunderset("Brown ring ")([Fe(H_(2)O)_(5)NO]SO_(4))`
`underset((F))(HO)-overset(ddot)(N)=overset(ddot)(N)-OHoverset(Delta)(rarr)N_(2)O+underset((E))(H_(2)O)`
`underset((A))(NH_(4)NO_(3))" "underset((D))(N_(2)O)+underset((E))(2H_(2)O)`
Discussion
198.

Colourless salt (A) on heating with NaOH gives gas (B). When reaction of (A) with NaOH was complete, solution obtained on reacting `FeSO_(4)` and conc. `H_(2)SO_(4)` gave a brown coloured ring (C ) between two layers. (A) on heating strongly forms (D ) and (E). Compound (E ) is neutral oxide of a dibasic acid (F). What is compound (A)A. `NH_(4)NO_(3)`B. `NaNO_(3)`C. `KNO_(3)`D. None of these

Answer» Correct Answer - A
`underset((A))(NH_(4)NO_(3))+NaOHoverset(Delta)(rarr)underset((B))(NH_(3))+NaNO_(3)+H_(2)O`
`NO_(3)^(-)+FeSO_(4)+H_(2)SO_(4)rarrunderset("Brown ring ")([Fe(H_(2)O)_(5)NO]SO_(4))`
`underset((F))(HO)-overset(ddot)(N)=overset(ddot)(N)-OHoverset(Delta)(rarr)N_(2)O+underset((E))(H_(2)O)`
`underset((A))(NH_(4)NO_(3))" "underset((D))(N_(2)O)+underset((E))(2H_(2)O)`
Discussion
199.

An aqueous solution of colourless metal sulphate `M`, gives a white precipitate with `NH_(4)OH`.This was soluble in excess of `NH_(4)OH`. On passing `H_(2)S` through this solution a white precipitate is formed.The metal `M` in the salt is:A. `Ca`B. `Ba`C. `Al`D. `Zn`

Answer» Correct Answer - D
`Zn^(2+) + 2NH_(4)OH to Zn(OH)_(2) darr("white")+2NH_(4)^(+)`,
`Zn(OH)_(2)+4NH_(4)OH to Zn(NH_(3))_(4)+6H_(2)O`
`Zn^(2+) + S^(2-) to ZnS` (white)
Discussion
200.

The brown ring complex compound is formulated as `[Fe(H_(2)O)_(5)NO]SO_(4)`. The oxidation state of `Fe` isA. 1B. 2C. 3D. 0

Answer» Correct Answer - A
Discussion