Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydroxides) two ores [X] and [Y] show the following reactivity. (i)[X] on calcination gives a black solid (S), carbon dioxide and water. (ii)[X] Dissolved in dilute HCl, on reaction with Kl gives a white precipitate (P) and iodine. (iii)[Y] on roasting gives metal (M) and a gas (G_(1)) which turns acidified K_2Cr_2O_7 solution green. (iv)[Y] on reaction with dil.HCl givesa white precipitate (Q) and another gas (G_2) which turns lead acetate solution black, and also reacts with gas (G_1) to precipitate colloidal sulphur in presence of moisture. Reaction involved: (i)CuCO_3. Cu(OH)_2oversetDeltatoCuOdarr("black")+CO_2+H_2O CuCO_3.Cu(OH)_2+4HCl to2CuCl_2+3H_2O+CO_2 (ii)2Cu^(2+)+4I^(-)toCu_2l^2 darr (P)("white")+l_2uarr (iii)2Cu_2S+3O_2to2Cu_2O+2SO_2(G_1) Cu_2S+2Cu_2Oto6Cu+SO_2 (iv)Cu_2S+2HCl to2CuCldarr(Q)("white")+H_2S(G_2) Pb^(2+)+H_2StoPbSdarr("black")+2H^(+) (v)SO_2(G_1)+2H_2S(G_2)overset("moisture")to3Sdarr+2H_2O Which of the following statements is correct about [Y] ?

Answer»

[Y] is converted to metal (M) by self reduction
Carbonate extract of [Y] GIVES yellow PRECIPITATE with SUSPENSION of `CdCO_3`
[Y] is chalcocites or chalcopyrites
All of these

Solution :It is sulphide ore (`Cu_2S` or `CuFeS_2`) & is called as chalcopyrites or chalcocities , `S^(2-)` gives yellow precipitate of CDS with `CdCO_3`
Discussion
2.

Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydroxides) two ores [X] and [Y] show the following reactivity. (i)[X] on calcination gives a black solid (S), carbon dioxide and water. (ii)[X] Dissolved in dilute HCl, on reaction with Kl gives a white precipitate (P) and iodine. (iii)[Y] on roasting gives metal (M) and a gas (G_(1)) which turns acidified K_2Cr_2O_7 solution green. (iv)[Y] on reaction with dil.HCl givesa white precipitate (Q) and another gas (G_2) which turns lead acetate solution black, and also reacts with gas (G_1) to precipitate colloidal sulphur in presence of moisture. Reaction involved: (i)CuCO_3. Cu(OH)_2oversetDeltatoCuOdarr("black")+CO_2+H_2O CuCO_3.Cu(OH)_2+4HCl to2CuCl_2+3H_2O+CO_2 (ii)2Cu^(2+)+4I^(-)toCu_2l^2 darr (P)("white")+l_2uarr (iii)2Cu_2S+3O_2to2Cu_2O+2SO_2(G_1) Cu_2S+2Cu_2O to 6Cu+SO_2 (iv)Cu_2S+2HCl to 2CuCldarr(Q)("white")+H_2S(G_2) Pb^(2+)+H_2StoPbSdarr("black")+2H^(+) (v)SO_2(G_1)+2H_2S(G_2)overset("moisture")to3Sdarr+2H_2O The metal ores [X] and [Y] are respectively :

Answer»

Carbonate and sulphide ores
Sulphide and carbonate ores
Carbonate and hydroxide ores
Carbonate and oxide ores

Solution :`[X]=CuCO_3 CU(OH)_2 or 2CuCO_3. Cu(OH)_2 ,[Y]=Cu_2S or CuFeS_2`
Discussion
3.

Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydroxides) two ores [X] and [Y] show the following reactivity. (i)[X] on calcination gives a black solid (S), carbon dioxide and water. (ii)[X] Dissolved in dilute HCl, on reaction with Kl gives a white precipitate (P) and iodine. (iii)[Y] on roasting gives metal (M) and a gas (G_(1)) which turns acidified K_2Cr_2O_7 solution green. (iv)[Y] on reaction with dil.HCl givesa white precipitate (Q) and another gas (G_2) which turns lead acetate solution black, and also reacts with gas (G_1) to precipitate colloidal sulphur in presence of moisture. Reaction involved: (i)CuCO_3. Cu(OH)_2oversetDeltatoCuOdarr("black")+CO_2+H_2O CuCO_3.Cu(OH)_2+4HCl to2CuCl_2+3H_2O+CO_2 (ii)2Cu^(2+)+4I^(-)toCu_2l^2 darr (P)("white")+l_2uarr (iii)2Cu_2S+3O_2to2Cu_2O+2SO_2(G_1) Cu_2S+2Cu_2Oto6Cu+SO_2 (iv)Cu_2S+2HCl to 2CuCldarr(Q)("white")+H_2S(G_2) Pb^(2+)+H_2StoPbSdarr("black")+2H^(+) (v)SO_2(G_1)+2H_2S(G_2)overset("moisture")to3Sdarr+2H_2O The white precipitate (P) is of :

Answer»

<P>`Cu_2I_2`
`CU I_2`
`K_2[Cu l_4]`
NONE

Solution :`CuCO_3+2HCl to CuCl_2+CO_2 +H_2O , CuCl_2 + 2KltoCu l_2 + 2KCl ,2CU l_2 to Cu_2l_2 DARR (P) +I_2`
Discussion
4.

Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydroxides) two ores [X] and [Y] show the following reactivity. (i) [S] on calcination gives a black soil (S), carbon dioxide and water. (ii)[X]Dissolved in dil. HCl on reaction with KI gives a whiteprecipitate(P) and iodine. (ii)[Y] on roasting gives metal (M) and a gas (G_(1)) which turns a acidified K_(2)Cr_(2)O_(7) solution green. (iv) [Y]on reaction with dil. HCl gives a whitw precipitat (Q) and another gas (G_(2)) which turns lead acetate solution black. and also reacts wiht gas (G_(1)) to precipitate collodial suphur in presence of moisture. The M,S ,[X] and [Y] gives greenish blue flame. The metal ores [X]and [Y] are respectively:

Answer»

CARBONATE and SULPHIDE ores
Sulphide and carbonate ores
Carbonate and HYDROXIDE ores
Carbonate and OXIDE ores

Answer :C
Discussion
5.

Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydrixides) two ores [X] and [Y] show the following reactivity? (a) [X[] on calcination gives a black solid (S), water and a colourless gas which produces milkiness when passed through lime water. But this colourless gas does not decolorise acidified KMnO_(4). (b) [X] dissolved in diliute HCl. On reaction with KI gives a white precipitate(P) and iodine gas. (c) [Y] on roasting at high temperature gives metal (M) and gas (G_(1)) which turns starch iodate solution blue. (d) [Y] on reaction with dilute HCl gives a white precipatate (MS) and another gas (G_(1)) to precipitate colloidal sulpher in presence of moisture. M,S[X],[Y] gives greenish blue flame. The gas (G_(1)) can act as:

Answer»

OXIDISING agent
reducing agent
oxidising agent reducing agent
fluxing agent

Solution :`"COLOURLESS gas" to CO_(2)X to Cu^(2+), CO_(3)^(2-),OH^(-)`
G_(2) to H_(2)S, G_(1)to SO_(2),M to Cu, Sto CUO
Y to Cu^(2+), S^(2-)
Discussion
6.

Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydrixides) two ores [X] and [Y] show the following reactivity? (a) [X[] on calcination gives a black solid (S), water and a colourless gas which produces milkiness when passed through lime water. But this colourless gas does not decolorise acidified KMnO_(4). (b) [X] dissolved in diliute HCl. On reaction with KI gives a white precipitate(P) and iodine gas. (c) [Y] on roasting at high temperature gives metal (M) and gas (G_(1)) which turns starch iodate solution blue. (d) [Y] on reaction with dilute HCl gives a white precipatate (MS) and another gas (G_(1)) to precipitate colloidal sulpher in presence of moisture. M,S[X],[Y] gives greenish blue flame. Which of the following statements is correct about [Y]?

Answer»

[Y] is converted to metal (M) by self reduction.
Carbon extract of [Y] gives YELLOW precipitate with suspension of `CdCO_(3)`.
[Y] is COPPER glance or copper pyrite.
All of the above

Solution :`"Colourless gas" to CO_(2)X to Cu^(2+), CO_(3)^(2-),OH^(-)`
G_(2) to H_(2)S, G_(1)to SO_(2),M to Cu, Sto CUO
Y to Cu^(2+), S^(2-)
Discussion
7.

Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydrixides) two ores [X] and [Y] show the following reactivity? (a) [X[] on calcination gives a black solid (S), water and a colourless gas which produces milkiness when passed through lime water. But this colourless gas does not decolorise acidified KMnO_(4). (b) [X] dissolved in diliute HCl. On reaction with KI gives a white precipitate(P) and iodine gas. (c) [Y] on roasting at high temperature gives metal (M) and gas (G_(1)) which turns starch iodate solution blue. (d) [Y] on reaction with dilute HCl gives a white precipatate (MS) and another gas (G_(1)) to precipitate colloidal sulpher in presence of moisture. M,S[X],[Y] gives greenish blue flame. The metal ore [X] and [Y] are respectively:

Answer»

CARBONATE and SULPHIDE ORES
sulphide and carbonate ores
carbonate and HYDROXIDE ores
carbonate and OXIDE ores

Answer :a
Discussion
8.

Amongstthe trihalides of nitrogen which one has the highest dipole moment?

Answer»

`NF_(3)`
`NI_(3)`
`NCl_(3)`
`NBr_(3)`

ANSWER :2
Discussion
9.

Amongst the three isomers of nitrophenols, the one that is least soluble in water is _____.

Answer»

SOLUTION :o-nitrophenol DUE to CHELATION
Discussion
10.

Amongst the given set of reactants, the most appropritate for preparing 2^(@) amine is_____

Answer»

`2^(@)R-Br+NH_(3)`
`2^(@)R-Br+NaCn` followed by `H_(2)//Pt`
`1^(@)R-NH_(2)+RCHO` followed by `H_(2)//Pt`
`1^(@)R-Br(2MOL)`+POTASSIUM PHTHALIMIDE followed by `H_(3)O^(+)//`heat

Solution :`R-NH_(2)+RCHO underset("amination")overset("Reductive")to [R-N=CHR] overset(H_(2)//Pt)to underset(2^(@)" Amine")(R-NH-CH_(2)R)`
Discussion
11.

Amongst the given set of reactants the most appropriate for preparing 2^@ amine is __________________ .

Answer»

`(2^@ ) R-Br + NH_3 `
`(2^@ ) R-Br + NaCN `followed by `H_2 //Pt`
`(1^@ )R-NH_2 +RCHO `followed by `H_2//Pt`
`(1^@ )R-Br (2 mol) `+ potassium PHTHALIMIDE followed by `H_(3)O^(+)`/heat.

Solution :`R-NH_2+ RCHOunderset("AMINATION ") overset("Reductive ")to [R -N= CHR ] overset(H_2 //Pt)tounderset( 2^@"Amine")(R-NH -CH_2 R )`
Discussion
12.

Amongst the given set of reactants, the most appropriate for preparing 2^@amine is

Answer»

`(2^@ ) R-Br + NH_3 `
`(2^@ ) R-Br + NaCN `FOLLOWED by `H_2 //PT`
`(1^@ )R-NH_2 +RCHO `followed by `H_2//Pt`
`(1^@ )R-Br (2 mol) `+ potassium phthalimide followed by `H_(3)O^(+)`/heat.

Solution :`R-NH_2+ RCHOunderset("amination ") OVERSET("Reductive ")to [R -N= CHR ] overset(H_2 //Pt)tounderset( 2^@"AMINE")(R-NH -CH_2 R )`
Discussion
13.

Amongst the given set of reactants, the most appropriate for preparing 2_(@) amine is:

Answer»

`2^(@)R-Br+NH_(3)`
`2^(@)R-Br +NaCN` followed by `H_(2)//Pt`
`1^(@)R-NH_(2)+RCHO` followed by `H_(2)//Pt`
`1^(@)R-Br" (2 mol)" +"potassium phthalimide followed by "H_(3)O^(+)//"HEAT"`

Solution :`RNH_(2)+RCHOoverset("Reductive")underset("amination")RARR(R-N=NHR)OVERSET(H_(2)//Pt)rarr underset(2^(@)-" Amine")(R-NHCH_(2)R)`
Discussion
14.

Amongst the given set of reactants, the most appropriate for preparing 2^@ amine is ____.

Answer»

`2^@R-Br+NH_3`
`2^@R- Br + NACN` followed by `H_2`/PT
`1^@ R -NH_2 + RCHO` followed by `H_2`/Pt
`1^@R -Br` (2 mol) + Potassium phthalimide followed by `H_3O^+`/heat

Answer :C
Discussion
15.

Amongst the given set of reactants, the most appropriate for preparing 2^(@) amine is ______.

Answer»

`2^(@)R-Br+NH_(3)`
`2^(@)R-Br+NaCN` followed by `H_(2)//Pt`
`1^(@)R-NH_(2)+RCHO` followed by `H_(2)//Pt`
`1^(@)R-Br(2mol)+` potassium phthalimide followed by `H_(3)O^(+)//"heat"`

ANSWER :C
Discussion
16.

Amongst the given option, the compound(s) in which all the atoms are in one plane in all the possible conformations (if any), is/are

Answer»



`H_(2)C=C=CH-CH_(3)`
`H_(2)C=C=CH_(2)`

SOLUTION :CONSIDER conformers of (A) about c-2 and c-3. ONE of the conformer of (A) will not have all ATOMS in one PLANE.
Discussion
17.

Amongst the given options, the compound (s) in which all the atoms are in one plane in all the possible conformations (if any) is (are):

Answer»



`H_(2)C=C=O`
`H_(2)C=C=CH_(2)`

ANSWER :A::C
Discussion
18.

Amongst the follwong , the total number of compound soluble in aqueous HCl is :

Answer»


SOLUTION :
Discussion
19.

Amongst the following,the total number of species which are diamagnetic is ………………. . K_(4)[Fe(CN)_(6)],K_(3)[Cr(CN)_(6)],K_(3)[Co(CN)_(6)],K_(2)[Ni(CN)_(4)],[Co(NH_(3))_(6)]^(3+),K_(2)[TiF_(6)],[Pt(NH_(3))_(4)]^(2+)

Answer»


ANSWER :6
Discussion
20.

Amongstthefollowingstheoreswhich areroastedtoconvertthem into theircorrespondingmetaloxidesare : alumina,zinc blende,iron pyrites,copper pyrites,calamine,galena, chalcocite.

Answer»


SOLUTION : 5 (five, zinc BLENDE, IRON pyrites,copperpyrites, galena, chalocite).
Discussion
21.

Amongst the following , which is/are TRUE for S_(N)2 reaction ?

Answer»

The rate of reaction is independent of the concentration of the NUCLEOPHILE.
The nucleophile ATTACKS the carbon atom on the side of the MOLECULE opposite to the group beig displaced
The reaction proceedswith simultaneous BOND formation and bond rupture.
Both (B) and (C)

Answer :D
Discussion
22.

Amongst the following trihalides, which one is least basic?

Answer»

`NF_(3)`
`NCl_(3)`
`NBr_(3)`
`NI_(3)`

Answer :A
Discussion
23.

Amongst the following, total number of compounds soluble in sodium bicarbonate are: 2,4,6-trinitrophenol, benzoic acid, salicyclic acid, acetyl chloride, acetic anhydride, trifluoroethanol, acetamide, benzenesulphonic acid.

Answer»


Solution :Six compounds, i.e., 2,4,6-trinitrophenol, benzoic acid, salicylic acid, ACETYL chloride, acetic ANHYDRIDE and benzenesulphonic acid all decompose `NaHCO_(3)` and HENCE DISSOLVE in it.
Discussion
24.

Amongst thefollowing, totalnumber ofmetalswhichoccurin thenativestate intheearth'scrustare:Fe, Zn, Na, Au, Ni, Sb, Sn, Pt, Hg.

Answer»


SOLUTION :`2` (TWO, i.e.,Auand PT)
Discussion
25.

Amongst the following, total number of compounds soluble in sodium bicarbonate are: 2,4,6-trinitrophenol, benzoic acid, salicylic acid, acetyl chloride, acetic anhydride, trifluoroethanol, acetamide, benzenesulphonic acid

Answer»


Solution :Six compounds, i.e., 2,4,6-trinitrophenol, BENZOIC acid, salicylic acid, acetyl chloride ACETIC anhydride and benzene sulphonic acid decompose `NaHCO_(3)` and hence dissolve in it.
Discussion
26.

Amongst the following the total number of the compounds i.e. oxide soluble in aqueous NaOH is : Ag_2O, Al_2O_3,ZnO, SnO,PbO,CuO,BeO,BaO,CaO

Answer»


SOLUTION :`BeO(s)+2NaOH(AQ)toNa_2BeO_2(aq)+H_2O`
`Al_2O_3(s)+2NaOH(aq)to2NaAlO_2(aq)+H_2O`
`ZNO(s)+2NaOH(aq)toNa_2ZnO_2(aq)+H_2O`
`SnO(s)+2NaOH(aq)to Na_2SnO_2(aq)+H_2O`
`PbO(s)+2NaOH(aq)toNa_2PbO_2(aq)+H_2O`
Discussion
27.

Amongst the following the total number of species which does/do not exist is : SF_6,BF_6^(3-), SF_4, OF_4, AIF_6^(3-),PH_5, PCl_5, NCl_5, SCl_6

Answer»


Solution :(1)Amongst hexahalides of sulphur , only `SF_6` is exceptionally STABLE for steric reason.In `SCl_6`, smaller S cannot accommodate six larger `Cl^(-)` ions.
(2)`PH_5` does not exist as there is large difference in the energies of s,p and d orbitals of P and hence it does not undergo `sp^3d` hybridisation.
(3)`NCl_5` does not exist as there is no d-orbitals with N.
(4)`BF_6^(3-)` does not exist as there is no VACANT d-orbitals in B and hence it cannot exceed its covalency beyond four.
(5)OXYGEN cannot exceed its covalency as it does not have d-orbital.
Discussion
28.

Amongstthefollowing ,the totalnumber ofores whichmaybeconcentratedbyfrothfloatation process is :haematite,bauxine, galena, copper pyrites, sphalerite,cassiterite, calamine, argentite , chalocite.

Answer»


Solution :4 (FOUR, i.e.,GALENA , copperpyrites, sphalerite , CHAL- cocite ).Pleasenote that althoughargentite `(Ag_2 S ) `isa sulphideore,it isnotconcentratedbyfrothfloatation process sinceitssilvercontentislow. It isbetterconcentratedbyleachingwith NACN.
Discussion
29.

Amongst the following, the total number of orders which are correct with respect to the property indicated against each is : (i)MggtAlgtSigtP: Covalent radius (ii)Na^+ltO^(2-)ltF^(-)ltN^(3-):Ionic size. (iii)Al^(3+)ltMg^(2-)ltLi^(+)ltK^+:Ionic size. (iv)CltSigtPgtN:Electron affinity value. (v)NltCltOltF:Electron affinity value (vi)FgtClgtBrgtI:Electron affinity value (vii)SigtMggtAlgtNa:First ionisation energy (viii)OgtFgtNgtC:Second ionisation energy (ix)NgtPgtSbgtAs:Third ionisation energy

Answer»


Solution :(ii)`NA^(+)ltF^(-)LTO^(2-)LTN^(3-)`
(VI)`ClgtFgtBrgtI`
(ix)`NgtPgtAsgtSb`
Discussion
30.

Amongst the following, the total number of dimeric halides of group 16^(th) elements which undergo disproportionation is . S_2F_2,S_2Cl_2,S_2Br_2,Se_2Cl_2,Se_2Br_2

Answer»


SOLUTION :All udergo DISPROPORTIONATION as GIVEN below.
`2SeCl_2 to SeCl_4 + 3Se`
Discussion
31.

Amongst the following , the total number of compounds whose aqueous solutions turns red litmus paper blue is {:(KCN,K_(2)SO_(4),(NH_(4))_(2)C_(2)O_(4),NaCl,Zn(NO_(3))_(2)),(FeCl_(3),K_(2)CO_(3),NH_(4)NO_(3),LiCN,):}

Answer»


Solution :Basic solutions will CONVERT RED litmus BLUE.
`{:(KCN),(K_(2)CO_(3)),(LCN):}}`, their aqueous solution will be basic due to anionic hydrolysis.
Discussion
32.

Amongst the following, the total number of compounds soluble in concentrated NH_(3) solution is: (A)Ag_(2)CrO_(4) , (B)Cu(OH)_(2).CuSO_(4) , ( C)PbSO_(3) , (D)Al(OH)_(3) , (E)Ni(OH)_(2) (F)Zn_(3)(PO_(4))_(2) , (G)BaSO_(4) , (H)Bi(OH)_(2)NO_(3) , (I)Mn(OH)_(2)

Answer»


SOLUTION :(A)`Ag_(2)CrO_(4) darr ("YELLOW") + NH_(3) to [Ag(NH_(3))_(2)]^(+) +CrO_(4)^(2-)`
(B)`Cu(OH)_(2).CuSO_(4) darr ("blue") + 8NH_(3) to 2[Cu(NH_(3))_(4)]^(2+)+2OH^(-)`
( C)`PbSO_(3) darr ("white") +4OH^(-) to [Pb(OH)_(4)]^(2-) + SO_(3)^(2-)`
Soluble in sodium hydroxide not in `NH_(3)`
(D)Soluble in sodium hydroxide not in `NH_(3)`
(E)`Ni(OH)_(2) darr ("green") + 6NH_(3) to [Ni(NH_(3))_(6)]^(2+) ("DEEP blue colouration") + 2OH^(-)`
(F)`Zn_(3)(PO_(4))_(2) darr ("white") + 12NH_(3) to 3[Zn(NH+_(3))_(4)]^(2+) + 2PO_(4)^(3-)`
(G)Insoluble in `NH_(3)` soluble appreciably in boiling concentrated `H_(2)SO_(4)`
(H)`Bi(OH)_(2) NO_(3)` is insoluble in `NH_(3)`
(I)Insoluble in `NH_(3)` but soluble in ammonium salts liberating `NH_(3)`
Discussion
33.

Amongst the following, the total number of compounds soluble in concentrated NH_3 solution is: (A)Ag_2CrO_4, (B)Cu(OH)_2 .CuSO_4, (C )PbSO_3 , (D)Al(OH)_3 , (E)NI(OH)_2 (F)Zn_3(PO_4)_2, (G)BaSO_4, (H)Bi(OH)_2NO_3 , (I)Mn(OH)_2

Answer»


Solution :(A)`Ag_2CrO_4darr(yellow)+NH_3to[Ag(NH_3)_2]^(+)+CrO_4^(2-)`
(B)`Cu(OH)_2. CuSO_4 darr (blue )+8NH_3 to 2[Cu(NH_3)_4]^(2+)+SO_4^(2-)+2OH^(-)`
(C )`PbSO_3darr(white)+4OH^(-)to[PB(OH)_4]^(2-)+SO_3^(2-)`
Soluble in sodium hydroxide not in `NH_3`
(D)Soluble in sodium hydroxide not in `NH_3`
(E)`Ni(OH)_2darr(GREEN )+6NH_3to[ni(NH_3)_6]^(2-)`(deep blue colouration ) +`2OH^-`
(F)`Zn_3(PO_4)_2darr(white)+12NH_3to3[Zn(NH_3)_4]^(2-)+2PO_4^(3-)`
(G)Insoluble in `NH_3` , soluble appreciably in boiling concentrated `H_2SO_4`
(H)`Bi(OH)_2NO_3` is insoluble in `NH_3`
(I)Insoluble in `NH_3` but soluble in AMMONIUM salts liberating `NH_3`
Discussion
34.

Amongst the following, the total number of compounds soluble in aqueous NaOH is :

Answer»


SOLUTION :
Discussion
35.

Amongst the following, the total number of compound soluble in concentrated NH_(3) solution is (a) Ag_(2)CrO_(4) (b) Cu(OH)_(2),CuSO_(4) (c) PbSO_(3) ltBrgt (d) Al(OH)_(3) (e) Ni(OH)_(2) (f) Zn_(3)(PO_(4))_(2) (g) BaSO_(4) (h) Bi(OH)_(2)NO_(3) (i) Mn(OH)_(2).

Answer»


Solution :(a),(b) and (c) are soluble in sodium HYDROXIDE not in `NH_(3)`(d) Soluble in sodium hydroxide not in `NH_(3)`.
(e) `Ni(OH)_(2)darr(green)+6NH_(3)to[Zn(NH_(3))_(4)]^(2+)("Deep blue COLOURATION"))+2OH^(-)`
(f)
`Zn_(3)(PO_(4))_(2)darr(WHITE)+12NH_(3) to 3[Zn(NH_(3))_(4)]^(2+)+2PO_(4)^(3-)`
(g) Insoluble in `NH_(3)`, soluble appreaciable in boiling concentrated `H_(2)SO_(4)`.
(h) `Bi(OH)_(2)NO_(3)` is insoluble in `NH_(3)`.
(i) Insoluble in `NH_(3)` but soluble in ammonium salts liberating `NH_(3)`.
Discussion
36.

Amongst the following, the total number of biodegradable polymers are: Nylon-6, 6, PHBV, cellulose, PVC, glyptal, dextron, nylon-2-nylon 6, PAN.

Answer»


ANSWER :D
Discussion
37.

Amongst the following, the strongest reducing agent is .............

Answer»

<P>`P_(2)O_(6)^(4-)`
`P_(2)O_(7)^(4-)`
`H_(2)PO_(2)^(-)`
`H_(3)PO_(4)`

Solution :Phosphorus is in (+1) oxidation state in `H_2PO_2`. HENCE, it act as strongest reducing agent.
Discussion
38.

Amongst the following, the strongest base is

Answer»

`2, 4, 6-` trinitroaniline
`2, 4, 6-`trimethylaniline
Aniline
`N, N -` dimethylaniline

Solution :
Three electron RELEASING alkyl groups increase electron density on N ATOM and hence increase BASIC NATURE.
Discussion
39.

Amongst the following,the strongest base in aqueous medium is ______________ .

Answer»

`CH_3 NH_2`
`NC CH_2 NH_2`
`(CH_3)_2 NH`
`C_6H_5NHCH_3`

Solution :`(CH_3)_2 NH` being a `2^@`amine is more basic than `CH_3 NH_2(1^@ ). NC C_2 NH_2`is LESS basic than `CH_3 NH_2`due to-I effect of CN group. `C_6 H_5 NHCH_3` is less basic than `CH_3 NH_2` as well as `(CH_3 )_2 NH` due to delocalization of lone PAIR of electrons on the N-atom into thebenzene ring. Thus, `(CH_3)_2NH` is the strongest base.
Discussion
40.

Amongst the following, the strongest base in aqueous medium is

Answer»

`CH_3 NH_2`
`NC CH_2 NH_2`
`(CH_3)_2 NH`
`C_6H_5NHCH_3`

SOLUTION :`(CH_3)_2 NH` being a `2^@`amine is more BASIC than `CH_3 NH_2(1^@ ). NC C_2 NH_2`is less basic than `CH_3 NH_2`due to-I effect of CN group. `C_6 H_5 NHCH_3` is less basic than `CH_3 NH_2` as well as `(CH_3 )_2 NH` due to delocalization of lone pair of electrons on the N-atom into thebenzene ring. Thus, `(CH_3)_2NH` is the STRONGEST BASE.
Discussion
41.

Ammong the following the one which can exist in free state as a stable compound is:

Answer»

`C_7H_9O`
`C_8H_12O`
`C_6H_11O`
`C_10H_17O_2`

Solution :Degree of unsaturation = `(Sigman(v-2))/2+1`
n=no. of atoms of a particular type
v=valency of the atom
`C_7H_9O: DU=(7(4-2)+9(1-2)+1(2-2))/2 +1 =3.5`
`C_8H_12O : DU=(8(4-2)+12(1-2)+1(2-2))/2 +1=3`
`C_6H_11O :DU=(6(4-2)+1(1-2)+1(2-2))/2 +1=1.5`
`C_10H_17O_2 : DU=(10(4-2)+17(1-2)+2(2-2))/2 +1=2.5`
Molecules with fractional degree of unsaturation cannot exist with STABILITY
Discussion
42.

Amongst the following, the number of drugs used as tranquilizers are: Brufern , diclofenac , sodium veronal, sertonin ,equanil, secronal, cispiren

Answer»


ANSWER :5
Discussion
43.

Amongst the following, the number of drugs used as tranquillizers are : Brufern, diclofenac, sodium veronal, valium, serotonin, equanil, secronal, cispiren.

Answer»


ANSWER :5
Discussion
44.

Amongst the following the most stable compound is

Answer»

`[Fe(H_(2)O)_(6)]^(3+)`
`[Fe(C_(2)O_(4))_(3)]^(3-)`
`[Fe(NH_(3))_(6)]^(3+)`
`[FeCl_(6)]^(3-)`

Answer :B
Discussion
45.

Amongst the following, the most stable complex is

Answer»

`[Fe(H_(2)O)_(6)]^(3+)`
`[Fe(NH_(3))_(6)]^(3+)`
`[Fe(C_(2)O_(4))_(3)]^(3-)`
`[FeCl_(6)]^(3-)`

Solution :In each of the given COMPLEX, Fe is in +3 STATE. As `C_(2)O_(4)^(2-)` is didentate chelating ligand, it forms CHELATE rings and HENCE is the most stable complex.
Discussion
46.

Amongst the following, the most stable complex is :

Answer»

`[FE(H_(2)O)_(6)]^(3+)`
`[Fe(NH_(3))_(6)]^(3+)`
`[Fe(C_(2)O_(4))_(3)]^(3-)`
`[FeCl_(6)]^(3-)`

Solution :Complexes CONTAINING didentate or polydentate ligands are more stable than those containing monodentate ligands. In each of the given complex, Fe is in +3 STATE. As `C_(2)O_(4)^(2-)` is didentate chelating ligand, hence is the most stable complex.
Discussion
47.

Amongst the following the most reactive alkyl halide is

Answer»

`C_2 H_5 F`<BR>`C_2 H_5 CL`
`C_2 H_5 Br`
`C_2 H_5 I`

ANSWER :D
Discussion
48.

Amongst the following, the molecule/ion that is linear is:

Answer»

`SO_(2)`
`CO_(2)`
`CkO_(2)^(-)`
`NO_(2)^(-)`

Solution :Molecule or ion having sp hybridisation and no LONE pair of ELECTRONS is linear.
Hybridisation = `(1)/(2)` [No. of e in valence shell of central atom + No: monovalent atoms + Charge on anion - Charge on cation]
(a) `SO_(2)`
`H=(1)/(2)(6+0+0-0)=3sp^(2)` (linear shape)
(B) `CO_(2)`
`H=(1)/(2)(4+0+0-0)=2sp` (linear shape)
`CiO_(2)`
`H=(1)/(2)(7+0+1-0)-4sp^(3)` (tetrahedral)
`(d) NO_(2)^(-)`
`H=(1)/(2)(5+0+1-0)=3sp^(3)` (trigonal planar)
`:. CO_(2)` has linear shape.
Discussion
49.

Amongst the following the metals which become passive when dipped in conc. HNO_(3) are Sn, Pb, Fe, Cr, Zn, Ni, Hg, Al, Cu.

Answer»


SOLUTION :Fe, CR, Ni and Al BECOMES PASSIVE when dipped in conc. `HNO_(3)`.
Discussion
50.

Amongst the following, the maximum number of isoelectronic molecules/ions are XeO_(3), BrO_(3)^(-), ClF, XeF_(2), OF_(2), XeF_(4), ICl_(4)^(-), ClO^(-), IBr_(2)^(-).

Answer»


Solution :CIF (17 + 9 = 26), `OF_(2)` (8 + 2 `xx` 9 = 26), `CLO^(-)` (17 + 8 + 1 = 26).
Discussion