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.

The complex that violates the E AN:

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POTASSIUM ferrocyanide
Potassium ferricyanide
Nickel carbonyl,
COBALT (HI) HEXAMINE chloride

Answer :B
Discussion
2.

The complex showing a spin-only magnetic moment of 2,82 B.M. is

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 `Ni(CO)_(4)`
 `(NiCI_(4)]^(2-)`
`Ni(PPh_(3))_(4)`
 `[Ni(CN)_(4)^(2-)`

Solution :`Nicl_(4)]^(`2-), O.S. of Ni = +2`
`Ni(28) = 3d^(8) 4s^(2)`
`Ni^(+2) = 3d^(8) `

No. of unpaired electrons =2
MAGNETIC moment `MU = 2.82 BM`
Discussion
3.

The complex [Pt(NH_3)_6]Cl_4 furnishes:

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5 ions
6 ions
4 ions
2 ions

Answer :A
Discussion
4.

The complex, [Pt(py)(NH_3)BrCl]will have how many geometrical isomers ?

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2
3
4
0

Answer :B
Discussion
5.

The complex [Pt(py)(H_(2)O)(NH_(3))(NO_(2))ClBr] has :

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10 geometrical isomers, each ONE is OPTICALLY active
10 geometrical isomers, five of them are optically active
15 geometrical isomers, each one is optically active
15 geometrical isomers, each one is optically inactive

Answer :C
Discussion
6.

The complex, [Pt(Py)(NH_(3))BrCl] will have how many geometrical isomers ?

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3
4
0
2

Answer :A
Discussion
7.

The complex [Pt(NH_(3))_(4)]^(2+) has structure :-

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SQUARE planer
Tetrahedral
Pyramidal
Pentagonal

Answer :A
Discussion
8.

The complex [Pt(NH_(3))_(4)]^(2+) has ……….structure.

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Square planar
tetrahedral.
pyramidal
pentagonal

Solution :`5D^(8)` configuration have HIGHER CFSE and the COMPLEX is thus square planer and diamagnetic.
`PT^(2+)=[Xe]4f^(14)5d^(8)`
Discussion
9.

The complex [Pt(NH_(3))_(4)]^(2+) has ……….structure :

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SQUARE PLANAR
tetrahedral
pyramidal
pentagonal

Solution :(a) `DSP^(2) to "Square planar"`
Discussion
10.

The complex [Ni(CN)_(4)]^(2-) is diamagnetic and it involves the following hybridisation of nickel :

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`SP^(3)`
`DSP^(2)`
`d^(2)sp^(3)`
`sp^(3)d` .

Solution :It is square planar and INVOLVES `dsp^(2)` hybridisation.
Discussion
11.

The complex K_(4)[Zn(CN)_(4)(O_(2))_(2)] is oxidised into K_(2)[Zn(CN)_(4)(O_(2))_(2)], then which of the following is correct ?

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Zn (II) is oxidised into Zn (IV)
Paramagnetic moment DECREASES
`O-O` bond length increases
Paramagnetic moment increases

SOLUTION :`OVERSET(+4)K_(4)[overset(+2)Zn(overset(-4)CN)_(4)(overset(-2)O_(2))_(2)] to overset(+2)K_(2)[overset(+2)Zn(overset(-4)CN)_(4)(overset(0)O_(2))_(2)]`
`{:(""O_(2)^(-),to,""O_(2)^(-)),("(Paramagnetic)",,"(Paramagnetic)"),(" "B.O.=1.5,," "B.O.=2.0),(""(2u.P.e^(-)),,""(2u.P.e^(-))):}`
Discussion
12.

The complex iron [Co(H_(2)O)_(5) (ONO)]^(2+) and [Co(H_(2)O)_(5) NO_(2)]^(2+) are called

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LINKAGE isomers
IONIZATION isomers
COORDINATION isomers
GEOMETRICAL isomers

ANSWER :A
Discussion
13.

The complex ions [Fe(CN)_(6)]^(3-) and [Fe(CN)_(6)]^(4-) :

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Are both octahedral and PARAMAGNETIC
Are both octahedral and diamagnetic
Have same STRUCTURE but OPPOSITE magnetic character
Have DIFFERENT structure but opposite magnetic character

Solution :`[Fe(CN)_(6)]^(3-)` is paramagnetic while `[Fe(CN)_(6)]^(4-)` is diamagnetic.
Discussion
14.

The complex K_3[Fe(CN)_6] should have a spin only magnetic moment of

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`SQRT3` B.M.
`2SQRT5` B.M.
`SQRT5` B.M.
`SQRT6` B.M.

ANSWER :A
Discussion
15.

The complex ion [Ni(NH_(3))_(4)]^(2+) on treatment with conc. HCl gives two compounds (A) and (B) having the formula [Ni(NH_(3))_(2)Cl_(2)]. Compound (A) can be converted into compound (B) by boiling with dilute HCl. The solution of (A) reacts with oxalic acid to form [Ni(NH_(3))_(2)(C_(2)O_(4))] while solution of (B) does not react with oxalic acid. Identify (A) and (B) and also show their geometry.

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Solution :`[Ni(NH_(3))_(4)]^(2+)+2HClrarrunderset((A) and (B))([Ni(NH_(3))_(2)Cl_(2)])+2 NH_(3)`
COMPOUND (A) is a cis-isomer which can easily form a chelate ring with the oxalate LIGAND

Both compound (A) and (B) are square planar and compound A (cis-form) can be CONVERTED into compound B (trans-form) by boiling with dilute HCL.
Discussion
16.

The complex ion which has no. ‘d’ electrons in the central metal atom is:

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`MnO_4^-`
`CO(NH_3)_6^(3+)`
`[FE(CN)_6]^(3+)`
`[CR(H_2O)_6]^(3+)`

Answer :A
Discussion
17.

The complex ion which has no 'd'-electrons in the central metal atom is

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`[MnO_(4)]^(-)`
`[Co(NH_(3))_(6)]^(3+)`
`[FE(CN)_(6)]^(3-)`
`[Cr(H_(2)O)_(6)]^(3+)`

SOLUTION :Oxidation state of Mn in `[MnO_(4)]^(-)` = +7 , hence it does not have any d-electrons PRESENT in it .
`Mn^(7+) (Z = 25) : [Ar] 4s^(0) 3d^(0)`
Discussion
18.

The complex ion which has no d electrons in the central metal atom is

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`[MnO_(4)]^(-)`
`[Co(NH_(3))_(6)]^(3+)`
`[FE(CN)_(6)]^(3-)`
`[Cr(H_(2)O)_(6)]^(3+)`d

Solution :In `MnO_(4)^(-)` the oxidation number of Mn is +7. Thus, `Mn^(7+)` has configuration `[Ar]3d^(0)4s^(0)` as all the electrons (`3d^(5)` and `4s^(2)`) are lost.
Discussion
19.

The complex ion in k_(4)[Fe(CN)_(6)] is ……… .

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ANSWER :`[FE(CN)_(6)]^(4-)`
Discussion
20.

The complex ion having minimum magnitude of triangle_circ (CFSE) in octahedral field is

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`[CoCl_6]^(3-)`
`[CO(CN)_6]^(3-)`
`[Co(H_2O)_6]^(3+)`
`[Co(NH_3)_6]^(3+)`

ANSWER :A
Discussion
21.

The complex ion has two optical isomers. Their correct configuration are :

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SOLUTION :(d) does not have COS or POS
Discussion
22.

The complex ion having minimum magnitude of Delta_o(CFSE) is

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`[CO(NH_(3))_(6)]^(3+)`
`[Cr(H_(2)O)_(6)]^(3+)`
`[Cr(CN)_(6)]^(3-)`
`[CoCl_(6)]^(3-)`

Solution :The magnitude of `Delta_(o)` follows the ORDER :
`Cl^(-) LT H_(2)O lt NH_(3)lt CN^(-)`
Discussion
23.

The complex ion [Fe(CN)_(6)]^(4-) contains:

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total of 36 electrons on `FE^(2+)` cation
`SP^(3)d^(2)` HYBRID orbitals with octahedral structure
total of 104 electrons
six sigma bonds

Answer :A
Discussion
24.

The complex ion [Cu(NH_3)_4]^(2+) has:

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The TETRAHEDRAL configuration with ONE UNPAIRED electron configuration
Square planar configuration with one unpaired electron
Tetrahedral configuration with all ELECTRONS paired
Square planar configuration with all electrons paired

Answer :B
Discussion
25.

The complex ion [Co(en)_2Cl_2]^(+)exhibits

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OPTICAL ISOMERISM and LINKAGE isomerism
Cis-trans isomerism and optical isomerism
cis-trans isomerism and linkage isomerism
Cis-trans isomerism only

Answer :B
Discussion
26.

The complex [Hgl_(3)]^(-)

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is TRIGONAL planar
has `SP^(2)`-hybridization
is paramagnetic
none of these

Solution :
Discussion
27.

The complex Hg[Co(CNS)_(4)] is named as :

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MERCURY tetrasulphocyanide COBALTATE (III)
Mercury tetrathiocyanato cobaltate (II)
Mercury tetrathiocyanato COBALT (III)
Mercury tetrathiocyanato cobaltate (O).

SOLUTION :The oxidation number of iron is +2.
Discussion
28.

The complex Hg[Co(CNS)_4] is correctly named as:

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MERCURY tetrathiocyanato COBALTATE(II)
Mercury COBALT tetrasulphocyano(II)
Mercury tetrasulphocyanide cobaltate(II)
Mercury sulphocyanate cobalt(II)

ANSWER :A
Discussion
29.

The complex forming ability of a transition metal depends upon

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availability of vacant d-orbital
high ionisation potential
small size of CATION or high CHARGE density
VARIABLE OXIDATION states

Solution :size, charge and availability of vacant d-orbitals
Discussion
30.

The complex [Fe(H_(2)O)_(5)NO]^(2+) is formed in the brown ring test for nitrates when freshly prepared FeSO_(4) solution is added to aqueous solution of NO_(3) followed by addition of cone. H_(2)SO_(4). Select correct statement about this complex.

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COLOUR change DUE to charge transfer.
It has iron in +1 OXIDATION state and nitrosyl as `NO^(+)`.
It has magnetic moment of 3.87 BM CONFIRMING three unpaired ELECTRONS in Fe.
All are correct statements.

Answer :D
Discussion
31.

The complex formed when Al_2 O_3 is leached from Bauxite using concentrated NaOH solution is,

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`Na[Al(OH)_(4)]`
`NaAl_(2)O_(4)`
`Na_(2)[Al(OH)_(3)]`
`Na_(2)AlO_(2)`

Solution : `Al_(2)O_(3)+2NaOH+3H_(2)Orightarrow2NA[Al(OH)_(4)]`
Discussion
32.

Thecomplex formedwhenAl_2O_3isleachedfrombauxineusingconcentratedNaOHsolutions is

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` NA[AL(OH)_4] `
` NaAl_2O_ 4`
`Na_2[Al(OH)_3] `
`Na_2AlO_2`

Solution : `Na[Al(OH)_4]`.
Discussion
33.

The complex [Fe(H_(2)O)_(5)NO]^(2+) is formed in the brown ring test for nitrates when freshly prepared FeSO_(4) solution is added to aq solution of NO_(3)(-) followed by addition of conc. H_(2)SO_(4). Select correct statement about this complex :

Answer»

colour changes due to charge transfer
it has iron in `+1` OXIDATION state and nitrosyl as `NO^(+)`
it has magnetic moment of 3.87 B.M. confirming three unpaired ELECTRONS in FE
all are correct statements

Answer :D
Discussion
34.

The complex [Fe(H_(2)O)_(5)NO]^(2+) is formed in the 'brown ring test' for nitrates. Choose the incorrect statement for the complex.

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Its magnetic moment is approximately 3.9 BM
The oxidation STATE of IRON is `+1`
The hybridization of central metal ion is `sp^(3)d^(2)`
The brown colour of the RING is due to `d-d` transition

Solution :`[overset(+1)(Fe) (H_(2)O)_(5) overset(+)(N)O]^(2+)`
`sp^(3) d^(2) , d^(7)` config.

3 UNPAIRED `e^(-)`
Discussion
35.

The complex [Fe(H_(2)O)_(5)NO]^(2+) is formed in Brown ring test for nitrates select correct statement for the complex ?

Answer»

Hybridisation of iron is `sp^(3)d^(2)`
Iron and nitrosyl has +1 oxidation state
It has magnetic moment of 3.87 B.M.
All are correct

Solution :In `[FE(H_(2)O)_(5)NO]^(+2)`
`Fe^(+)=3d^(6)4s^(1)`
in presence of ligand `Fe^(+)=3d^(7)4s^(0)`
hybridisation `=sp^(3)d^(2)`,
magnetic moment.s = 3.87 B.M.
Discussion
36.

The complexexhibits :

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linkage ISOMERISM, geometrical isomerism and OPTICAL isomerism
linkage isomerism, ionisatiion isomerism and geometrical isomerism
linkage isomerism, ioniasation isomerism and optical isomerism
ionisation isomerism , optical isomerism and geometrical isomerism

Solution :b) The complex is EXPECTED to exhibit:
b) linkage isomerism: `[Co(NH_(3))_(4)CL(NO_(2))_(2)]` and `[Co(NH_(3))_(4)(ONO)_(2)]Cl`
ii) ionisation isomerism
`[Co(NH_(3))_(4)(NO_(2))_(2)]Cl ltimplies[Co(NH_(3))_(4)(NO_(2))_(2)]^(+)+Cl^(-)`
Discussion
37.

The complex entity which shows geometrical as well as optical isomerism, is :

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`[Co(gly)_(3)]`
`[Co(gly)(NH_(3))_(4)]^(2+)`
`[CoCl_(2)(NH_(3))_(4)]`
All of these

Solution :`[M(AB)_(3)) IMPLIES` Both G.I. and O.I. possible.
Discussion
38.

The complex [Cr(H_(2)O)_(4)Br]Cl gives the test for :

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`BR^(-)`
`CL^(-)`
`CR^(3+)`
`Br^(-)` and `Cl^(-)` both

Solution :N//A
Discussion
39.

The complex [Co(NH_(3))_(5)F]^(2+) reacts with water according to the equation, [Co(NH_(3))_(5)F]^(2+)+H_(2)O rarr [Co(NH_(3))_(5)H_(2)O]^(3+)+F^(-) The rate of reaction = "rate constant" xx ["complex"]^(n)xx[H^(+)]^(m)=K["complex"]^(n)[H^(+)]^(m). The reaction is acid catalyzed, i.e., [H^(+)] does not change during the reaction. Thus, rate =K' ["complex"]^(n) where K'=K[H^(+)]^(m) Calculate m and n if they are integers from the following data at 25^(@)C. {:("[complete] M",[H^(+)]M,t_(1//2) ("hour"),t_(3//4)("hour")),(0.1,0.01,1,2),(0.2,0.02,0.5,1):} t_(3//4) is time required for three fourth completion of the reaction.

Answer»


SOLUTION :N//A
Discussion
40.

The complex [Cu(NH_(3))_(4)]^(2+) is :

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TETRAHEDRAL with one UNPAIRED ELECTRON
square planar with one unpaired electron
square planar and diamagnetic
tetrahedral and diamagnetic.

Answer :B
Discussion
41.

The complex [Co(NH_(3))_(6)][Cr(CN)_(6)]" and "[Cr(NH_(3))_(6)][Co(CN)_(6)] are the examples of which type of isomerism?

Answer»

`dsp^(2)`
`SP^(3)`
`d^(2)sp^(2)`
`d^(2)sp^(3)`

Solution :The complexes `[CO(NH_(3))_(6)][CR (CN)_(6)] " and" [Cr(NH_(3))_(6)][Co (CN)_(6)]` are the EXAMPLES of coordmation isomensms This isomerism occurs only in those complexes in which both cation and anion are complex. Tt occurs due to exchange of ligands between cation and anion.
Discussion
42.

The complex [Co(NH_(3))_(6)]^(3+) is an inner orbital complex whereas the [CoF_(6)]^(3-) is an outer orbital complex. The number of unpaired electrons in these two complexes are respectively :

Answer»

Zero and 4
4 and 4
6 and 2
3 and 4.

ANSWER :A
Discussion
43.

The complex[Co(NH_3)_5BR]SO_4 will give white ppt with:

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`PbCI_3`
`AgNO_3`
KI
None

Answer :A
Discussion
44.

The complex [Co(NH_(3))_(5)Br] SO_(4) will give white precipitate with

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`BaCl_(2)`
`AgNO_(3)`
`Kl`
NONE of these

Answer :A
Discussion
45.

The complex, [Co(NH_(3))_(4)Cl_(2)]^(+) is known to exist in two different coloured forms. This is due to

Answer»

ionisation isomerism
optical isomerism
GEOMETRICAL isomerism
linkage isomerism

Solution :`[Ma_(4)b_(2)]^(NPM)` formula compounds will exhibit geometrical isomerism, not optical isomerism.
Discussion
46.

The complex[Co(NH_(3))_(4)Cl_(2)]Br can exhibit :

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LINKAGE isomerism
Ionisation isomerism
COORDINATION isomerism
Ligand isomerism.

Answer :B
Discussion
47.

The complex [Co(NH_3)_3Cl_3]is :

Answer»

Neutral
Cationic
Anionic
None

Answer :A
Discussion
48.

The complex [Co(NH_3)_3Cl_3] when dissolved in water gives how many ions:

Answer»

2
4
3
zero

Answer :D
Discussion
49.

The complex compound which does not give precipitate with AgNO_(3) solution is

Answer»

`[CO(NH_3)_5Cl]Cl_2`
`[Co(NH_3)_6]Cl_3`
`[Co(NH_3)_4Cl_2]CL`
`[Co(NH_3)_3Cl_3]`

ANSWER :D
Discussion
50.

The complex compound act as oxygen transporter of human is …………

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Haemoglobin
Chlorophy `II`
CYANO cobalamine
Wilkinson compound

Answer :A::B
Discussion