Therefore, Cul does not have magnetic moment of 1.73 BM.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 20th July Morning Shift
According to the valence bond theory the hybridization of central metal atom is dsp2 for which one of the following compounds?
A.
$NiC{l_2}.6{H_2}O$
B.
${K_2}[Ni{(CN)_4}]$
C.
$[Ni{(CO)_4}]$
D.
$N{a_2}[NiC{l_4}]$
Correct Answer: B
Explanation:
According to VBT i.e. valence bond theory,
Electronic configuration of Ni = [Ar]3d84s2.
(a) NiCl2 . 6H2O
NiCl2 . 6H2O $\rightarrow$ NiCl2 + 6H2O
Oxidation number of Ni(x) = x + 2($-$1) = 0; where x, $-$1 and 2 are the oxidation number of Ni, oxidation number of Cl and number of Cl atoms respectively.
NiCl2 $\Rightarrow$ x + ($-$2) = 0 $\Rightarrow$ x = 2
Electronic configuration of Ni2+ = [Ar]3d84s0
Cl$-$ is a weak field ligand. So, no pairing of electrons occurs.
For C.N. = 6
(b) K2[Ni(CN)4]
K2[Ni(CN)4] $\rightarrow$ 2K+ + [Ni(CN)4]2$-$
x + 4($-$1) $-$ ($-$2) = 0; where x, 4, $-$1 and $-$2 are the oxidation number of Ni, number of CN ligands, charge on one CN and charge on complex.
[Ni(CN)4]2$-$ $\Rightarrow$ x $-$ 4 + 2 = 0 $\Rightarrow$ x = +2
Electronic configuration of Ni2+ $\Rightarrow$ [Ar]3d84s0
CN$-$ is a strong field ligand. So, pairing of electrons occur. For C.N. = 4
(c) Ni(CO)4
CO is neutral and strong field ligand. So, pairing of electrons occur.
Oxidation number of Ni is zero
Electronic configuration of Ni = [Ar]3d104s0
For C.N. = 4
(d) Na2[NiCl4]
Na2[NiCl4] $\rightarrow$ 2Na + [NiCl4]2$-$
x + 4($-$1) $-$ ($-$2) = 0; where x, 4, $-$1 and $-$2 are the oxidation number of Ni, number of CN ligands, charge on one CN and charge on complex.
[NiCl4]2$-$ $\Rightarrow$ x $-$ 4 + 2 = 0 $\Rightarrow$ x = +2
Electronic configuration of Ni2+ = [Ar]3d84s0
For C.N. = 4
Hence, only K2[Ni(CN)4] has dsp2 hybridization.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 20th July Morning Shift
The correct order of intensity of colors of the compounds is :
Correct order of intensity of colours of the compounds is
[NiCl4]2$-$ > [Ni(H2O)6]2+ > [Ni(CN)4]2$-$
Ni is in +2 oxidation state in all complexes. The intensity of colour depends on the strength of the ligand attached with the central metal atom because more strong ligand more splitting energy, less is intensity of colour. Strength of ligand is in the order CN$-$ > H2O > Cl$-$.
Splitting energy order [NiCl4]2$-$ < [Ni(H2O)6]2+ < [Ni(CN)4]2$-$
$\therefore$ Intensity of colour of compound
[NiCl4]2$-$ > [Ni(H2O)6]2+ > [Ni(CN)4]2$-$
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 18th March Evening Shift
The secondary valency and the number of hydrogen bonded water molecule(s) in CuSO4 . 5H2O, respectively, are :
A.
5 and 1
B.
4 and 1
C.
6 and 5
D.
6 and 4
Correct Answer: B
Explanation:
CuSO4.5H2O $ \Rightarrow $ [Cu(H2O)4]SO4.H2O
In CuSO4.5H2O, Cu is co-ordinated with 4 water molecule and two more oxygen atom from sulphate ion and fifth water molecule is hydrogen bonded.
So secondary valency = 4
No. of hydrogen bond per molecule = 1
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 18th March Morning Shift
The correct structures of trans-[NiBr2(PPh3)2] and meridonial-[Co(NH3)3(NO2)3], respectively, are
A.
B.
C.
D.
Correct Answer: D
Explanation:
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 17th March Evening Shift
Match List - I with List - II :
List - I
List - II
(a)
$[Co{(N{H_3})_6}][Cr{(CN)_6}]$
(i)
Linkage isomerism
(b)
$[Co{(N{H_3})_3}{(N{O_2})_3}]$
(ii)
Solvate isomerism
(c)
$[Cr{({H_2}O)_6}C{l_3}$
(iii)
Co-ordination isomerism
(d)
$cis - {[CrC{l_2}{(ox)_2}]^{3 - }}$
(iv)
Optical isomerism
Choose the correct answer from the options given below :
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 25th February Morning Shift
The hybridization and magnetic nature of ${[Mn{(CN)_6}]^{4 - }}$ and ${[Fe{(CN)_6}]^{3 - }}$, respectively are :
A.
sp3d2 and diamagnetic
B.
d2sp3 and paramagnetic
C.
sp3d2 and paramagnetic
D.
d2sp3 and diamagnetic
Correct Answer: B
Explanation:
${[Mn{(CN)_6}]^{4 - }}$
Mn2+ = 3d5 4s0
CN– is a strong field ligand.
$ \therefore $ Pairing will occur.
${[Fe{(CN)_6}]^{3 - }}$
Fe3+ = 3d54s0
CN– is a strong field ligand.
$ \therefore $ Pairing will occur.
2021
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 24th February Evening Shift
The calculated magnetic moments (spin only value) for species ${[FeC{l_4}]^{2 - }}$, ${[Co{({C_2}{O_4})_3}]^{3 - }}$ and $MnO_4^{2 - }$ respectively are :
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 1st September Evening Shift
The sum of oxidation states of two silver ions in [Ag(NH3)2] [Ag(CN)2] complex is _____________.
Correct Answer: 2
Explanation:
[Ag(NH3)2][Ag(CN)2] complex dissociates into [Ag(NH3)2]+ and [Ag(CN)2].
Oxidation of Ag in [Ag(NH3)2]+
Ag + 0 $\times$ 2 = + 1
Ag = + 1
Oxidation state of Ag in [Ag(CN)2]$-$
Ag + ($-$1) $\times$ 2 = $-$ 1
Ag $-$ 2 = $-$ 1
$\Rightarrow$ Ag = + 1
$\therefore$ Sum of oxidation states of two silver ions in [Ag(NH3)2][Ag(CN)2] complex is 2.
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 27th August Evening Shift
The number of optical isomers possible for [Cr(C2O4)3]3$-$ is ____________.
Correct Answer: 2
Explanation:
The number of optical isomers for [Cr(C2O4)3]3$-$ is two.
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 27th August Morning Shift
1 mol of an octahedral metal complex with formula MCl3 . 2L on reaction with excess of AgNO3 gives 1 mol of AgCl. The denticity of Ligand L is ____________. (Integer answer)
Its means that one Cl$-$ ion present in ionization sphere.
$\therefore$ formula = [MCl2L2]Cl
For octahedral complex coordination no. is 6
$\therefore$ L act as bidentate ligand
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 26th August Evening Shift
The overall stability constant of the complex ion [Cu(NH3)4]2+ is 2.1 $\times$ 1013. The overall dissociations constant is y $\times$ 10$-$14. Then y is __________. (Nearest integer)
Correct Answer: 5
Explanation:
Given ks = 2.1 $\times$ 1013
Kd = ${1 \over {{k_s}}}$ = 4.7 $\times$ 10$-$14
$\therefore$ y = 4.7 $ \approx $ 5
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 26th August Morning Shift
The ratio of number of water molecules in Mohr's salt and potash alum is ____________ $\times$ 10$-$1. (Integer answer)
Correct Answer: 5
Explanation:
Mohr's salt : (NH4)2 Fe(SO4)2 . 6H2O
The number of water molecules in Mohr's salt = 6
Potash alum : KAl(SO4)2 . 12H2O
The number of water molecules in potash alum = 12
So ratio of number of water molecules in Mohr's salt and potash alum
$ = {6 \over {12}}$
$ = {1 \over 2}$
= 0.5
= 5 $\times$ 10$-$1
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 27th July Evening Shift
3 moles of metal complex with formula Co(en)2Cl3 gives 3 moles of silver chloride on treatment with excess of silver nitrate. The secondary valency of Co in the complex is ___________.
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 27th July Morning Shift
The number of geometrical isomers possible in triamminetrinitrocobalt (III) is X and in trioxalatochromate (III) is Y. Then the value of X + Y is _______________.
trioxalatochromate (III) ion $\to$ [Cr(C2O4)3]3$-$[Co(NO2)3(NH3)3]
X + Y = 2 + 0 = 2.0
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 25th July Morning Shift
Three moles of AgCl get precipitated when one mole of an octahedral co-ordination compound with empirical formula CrCl3.3NH3.3H2O reacts with excess of silver nitrate. The number of chloride ions satisfying the secondary valency of the metal ion is ______________.
Correct Answer: 0
Explanation:
Mole of AgCl precipitated is equal to mole of Cl- present in ionization sphere.
Since none of Cl- is present in the co-ordination sphere. Therefore answer is zero.
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 22th July Evening Shift
The total number of unpaired electrons present in [Co(NH3)6]Cl2 and [Co(NH3)6]Cl3 is :
Correct Answer: 3
Explanation:
[Co(NH3)6]Cl2
Co2+ : [Ar]3d74s04p0
For this complex $\Delta$0 < P.E., so pairing of electron does not take place.
sp3d2 hybridisation
Total 3 unpaired electrons are present.
[Co(NH3)6]Cl3
Co3+ : [Ar]3d6 4s0 4p0
d2sp3 hybridistion
NH3 acts as SFL because $\Delta$0 > P.E.
So, here all electrons becomes paired.
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 20th July Evening Shift
An aqueous solution of NiCl2 was heated with excess sodium cyanide in presence of strong oxidizing agent to form [Ni(CN)6]2$-$. The total change in number of unpaired electrons on metal centre is _______________.
Correct Answer: 2
Explanation:
[Ni(CN)6]2-
Ni+4 $\to$ d6, CN- strong field ligand. So pairing will happen.
Here zero unpaired electron
NiCl2 $\to$ Ni2+ $\to$ d8
Cl- Weak field ligand.$\to$ two unpaired e-
$ \therefore $ Change = 2.
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 20th July Morning Shift
The spin-only magnetic moment value for the complex [Co(CN)6]4$-$ is __________ BM.
[At. no. of Co = 27]
Correct Answer: 2
Explanation:
[Co(CN)6]4$-$
x + 6 $\times$ ($-$1) = $-$4
where, x, 6, $-$1 and $-$4 are the oxidation number of Co, number of CN ligands, charge on one CN and charge on complex.
x = +2, i.e. Co2+
Electronic configuration of Co2+ : [Ar]3d7 and CN$-$ is a strong field ligand which can pair electron of central atom.
It has one unpaired electron (n) in 4d-subshell.
So, spin only magnetic moment ($\mu$) = $\sqrt {n(n + 2)} $ BM = $\sqrt {1(1 + 2)} $ BM = $\sqrt 3 $ BM
where, n = number of unpaired electrons
$\mu$ = $\sqrt 3 $ BM = 1.73 BM
Nearest integer = 2
2021
JEE Mains
Numerical
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 18th March Morning Shift
The total number of unpaired electrons present in the complex K3[Cr(oxalate)3] is _____________.
Correct Answer: 3
Explanation:
In ${K_3}\left[ {Cr\left( {{C_2}{O_4}} \right)} \right]$, oxidation number of Cr :
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 17th March Evening Shift
On complete reaction of FeCl3 with oxalic acid in aqueous solution containing KOH, resulted in the formation of product A. The secondary valency of Fe in the product A is __________. (Round off to the Nearest Integer).
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 16th March Evening Shift
[Ti(H2O)6]3+ absorbs light of wavelength 498 nm during a d $-$ d transition. The octahedral splitting energy for the above complex is ____________ $\times$ 10$-$19 J. (Round off to the Nearest Integer). h = 6.626 $\times$ 10$-$34 Js; c = 3 $\times$ 108 ms$-$1
Correct Answer: 4
Explanation:
Octahedral splitting energy = ${{hc} \over \lambda }$
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2021 (Online) 16th March Morning Shift
The equivalents of ethylene diamine required to replace the neutral ligands from the coordination sphere of the trans-complex of CoCl3 . 4NH3 is _________. (Round off to the Nearest Integer).
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 4th September Evening Slot
The molecule in which hybrid MOs involve only
one d-orbital of the central atom is :
A.
XeF4
B.
[Ni(CN)4]2–
C.
[CrF6]3–
D.
BrF5
Correct Answer: B
Explanation:
XeF4 = sp3d2
[Ni(CN)4]2– = dsp2
[CrF6]3– = d2sp2
BrF5 = sp3d2
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 4th September Morning Slot
The pair in which both the species have the
same magnetic moment (spin only) is :
A.
[Cr(H2O)6]2+ and [CoCl4]2–
B.
[Co(OH)4]2– and [Fe(NH3)6]2+
C.
[Mn(H2O)6]2+ and [Cr(H2O)]2+
D.
[Cr(H2O)6]2+ and [Fe(H2O)6]2+
Correct Answer: D
Explanation:
Species with same number of unpaired
electrons have equal magnetic moment.
Complex
Ligand
Ligand Type
Number of unpaired electrons
[Mn(H2O)6]2+
H2O
Weak Field Ligand
5
[Cr(H2O)]2+
H2O
Weak Field Ligand
4
[CoCl4]2–
Cl
Weak Field Ligand
3
[Fe(H2O)6]2+
H2O
Weak Field Ligand
4
[Co(OH)4]2–
OH
Weak Field Ligand
3
[Fe(NH3)6]2+
NH3
Weak Field Ligand
4
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 4th September Morning Slot
The number of isomers possible for
[Pt(en)(NO2)2] is :
A.
3
B.
1
C.
4
D.
2
Correct Answer: A
Explanation:
Total 3 geometrical isomers are possible.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 3rd September Evening Slot
The d-electron configuration of [Ru(en)3
]Cl2 and [Fe(H2O)6]Cl2
, respectively are :
A.
$t_{2g}^4e_g^2$ and $t_{2g}^6e_g^0$
B.
$t_{2g}^6e_g^0$ and $t_{2g}^6e_g^0$
C.
$t_{2g}^6e_g^0$ and $t_{2g}^4e_g^2$
D.
$t_{2g}^4e_g^2$ and $t_{2g}^4e_g^2$
Correct Answer: C
Explanation:
[Ru(en)3
]Cl2 :
Here CN = 6 so octahedral splitting happens.
'en' is strong field ligand so $\Delta $0 > P(pairing energy). That is why pairing of electrons happens.
$\Delta $0 = Energy gap between eg and t2g orbital.
[Fe(H2O)6]Cl2 :
Here CN = 6 so octahedral splitting happens.
H2O is weak field ligand so $\Delta $0 < P(pairing energy). That is why no pairing of electrons happens.
$\Delta $0 = Energy gap between eg and t2g orbital.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 3rd September Evening Slot
Complex A has a composition of H12O6Cl3Cr. If the complex on treatment with conc.H2SO4
loses
13.5% of its original mass, the correct molecular formula of A is :
[Given: atomic mass of Cr = 52 amu and Cl = 35 amu]
$ \therefore $ Around two moles of water are lost during
heating.
$ \therefore $ Formula of complex could be
[Cr(H2O)4Cl2]Cl.2H2O
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 3rd September Morning Slot
The complex that can show optical activity is :
A.
cis-[Fe(NH3)2(CN)4]–
B.
trans-[Cr(Cl2)(ox)2]3–
C.
trans-[Fe(NH3)2(CN)4]–
D.
cis-[CrCl2(ox)2]3– (ox = oxalate)
Correct Answer: D
Explanation:
It does not have symmetry, so, optically active.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 3rd September Morning Slot
The electronic spectrum of [Ti(H2O)6]3+ shows a single broad peak with a maximum at 20,300 cm-1
.
The crystal field stabilization energy (CFSE) of the complex ion, in kJ mol-1, is :
CFSE (in kJ) = ${{8120} \over {83.7}}$ = 97 kJ/mol
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 2nd September Evening Slot
The one that is not expected to show isomerism
is :
A.
[Pt(NH3)2Cl2]
B.
[Ni(NH3)4(H2O)2]2+
C.
[Ni(en)3]2+
D.
[Ni(NH3)2Cl2]
Correct Answer: D
Explanation:
[Pt(NH3)2Cl2] is dsp2 hybridisation and shows geometrical
isomerism.
[Ni(NH3)4(H2O)2]2+ is Octahedral, show
geometrical isomerism.
[Ni(en)3]2+ is Octahedral and shows optical
isomerism.
[Ni(NH3)2Cl2] is sp3 hybridisation and tetrahedral complex, therefore does not show geometrical and optical isomerism and structural isomerism.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 2nd September Evening Slot
Simplified absorption spectra of three
complexes ((i), (ii) and (iii)) of Mn+ ion are
provided below; their $\lambda $max values are marked
as A, B and C respectively. The correct match
between the complexes and their $\lambda $max values is
(i) [M(NCS)6](–6 + n) (ii) [MF6](–6 + n) (iii) [M(NH3)6]n+
A.
A-(i), B-(ii), C-(iii)
B.
A-(ii), B-(iii), C-(i)
C.
A-(ii), B-(i), C-(iii)
D.
A-(iii), B-(i), C-(ii)
Correct Answer: D
Explanation:
Stronger the ligand greater is splitting of d orbitals and smaller will be wavelength of light absorbed.
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 2nd September Morning Slot
For octahedral Mn(II) and tetrahedral Ni(II)
complexes, consider the following statements:
(I) both the complexes can be high spin.
(II) Ni(II) complex can very rarely be low spin.
(III) with strong field ligands, Mn(II) complexes
can be low spin.
(IV)aqueous solution of Mn(II) ions is yellow in
colour.
The correct statements are :
A.
(I), (III) and (IV) only
B.
(I) and (II) only
C.
(II), (III) and (IV) only
D.
(I), (II) and (III) only
Correct Answer: D
Explanation:
(I) Under weak field ligand, octahedral Mn(II) and tetrahedral Ni(II) both the complexes are high spin
complex.
(II) Tetrahedral Ni(II) complex can very rarely be low spin because square planar (under strong ligand)
complexes of Ni(II) are low spin complexes.
(III)With strong field ligands Mn (II) complexes can be low spin because they have less number of unpaired
electron (unpaired electron = 1) While with weak field ligands Mn(II) complexes can be high spin
because they have more number of unpaired electron (unpaired electron = 5)
(IV) Aqueous solution of Mn(II) ions is pink in colour.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 2nd September Morning Slot
Consider that a d6 metal ion (M2+) forms a
complex with aqua ligands, and the spin only
magnetic moment of the complex is 4.90 BM.
The geometry and the crystal field stabilization
energy of the complex is
A.
tetrahedral and – 1.6 $\Delta $t
+ 1P
B.
octahedral and –2.4 $\Delta $0 + 2P
C.
tetrahedral and –0.6 $\Delta $t
D.
octahedral and –1.6 $\Delta $0
Correct Answer: C
Explanation:
Spin only magnetic moment = 4.9 = $\sqrt {n\left( {n + 2} \right)} $
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 9th January Evening Slot
The correct order of the spin-only magnetic
moments of the following complexes is :
(I) [Cr(H2O)6]Br2 (II) Na4[Fe(CN)6]
(III) Na3[Fe(C2O4)3] ($\Delta $0 $>$ P)
(IV) (Et4N)2[CoCl4]
A.
(III) > (I) > (II) > (IV)
B.
(II) $ \approx $ (I) > (IV) > (III)
C.
(III) > (I) > (IV) > (II)
D.
(I) > (IV) > (III) > (II)
Correct Answer: D
Explanation:
(I) [Cr(H2O)6]Br2
H2O is weak field ligand so it can not pair up all the electrons.
Cr2+ : [Ar] 4s03d4 ($t_{2g}^3e{g^1}$)
Unpaired e– = 4
Magnetic moment = $\sqrt {24} $ = 4.89 BM
(II) Na4[Fe(CN)6]
CN- is strong field ligand so it pair up all the electrons.
Fe2+ = [Ar] 4s03d6 ($t_{2g}^6e{g^0}$)
Unpaired e– = 0
Magnetic moment = 0 BM
(III) Na3[Fe(C2O4)3]
As $\Delta $0 $>$ P, so pairing of electrons happens.
Fe3+ = [Ar] 4s03d5 ($t_{2g}^5e{g^0}$)
Unpaired e– = 1
Magnetic moment = $\sqrt 3 $ = 1.73 BM
(IV) (Et4N)2[CoCl4]
Cl-is weak field ligand so it can not pair up all the electrons.
Co2+ = [Ar] 4s03d7 ($e{g^4}t_{2g}^3$)
Unpaired e– = 3
Magnetic moment = $\sqrt {15} $ = 3.87 BM
Hence order of magnetic moment is
I > IV > III > II
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 9th January Evening Slot
The isomer(s) of [Co(NH3)4Cl2] that has/have
a Cl–Co–Cl angle of 90°, is/are :
A.
cis only
B.
cis and trans
C.
meridional and trans
D.
trans only
Correct Answer: A
Explanation:
[Co(NH3)4Cl2] has 2 geometrical isomers.
Among cis and trans isomers, cis isomer has Cl–Co–Cl angle of 90o.
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 9th January Morning Slot
Complex X of composition Cr(H2O)6Cln
has a spin only magnetic moment of 3.83
BM. It reacts with AgNO3 and shows
geometrical isomerism. The IUPAC
nomenclature of X is :
Spin only magnetic moment = $\sqrt {n\left( {n + 2} \right)} $ BM = 3.83
$ \Rightarrow $ n = 3
Chromium
in +3 oxidation state so molecular formula is
Cr(H2O)6Cln.
$ \therefore $ This formula have following isomers
(a) [Cr(H2O)6]Cl3 : react with AgNO3 but does
not show geometrical isomerism.
(b) [Cr(H2O)5Cl]Cl2.H2O react with AgNO3 but
does not show geometrical isomerism.
(c) [Cr(H2O)4Cl2]Cl.2H2O react with AgNO3 &
show geometrical isomerism.
(d) [Cr(H2O)3Cl3].3H2O does not react with
AgNO3 & show geometrical isomerism.
Compound will be
[Cr(H2O)4Cl2] Cl.2H2O
IUPAC NAME : Tetraaquadichlorido chromium(III) chloride dihydrate
2020
JEE Mains
MCQ
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 9th January Morning Slot
[Pd(F)(Cl)(Br)(I)]2– has n number of
geometrical isomers. Then, the spin-only
magnetic moment and crystal field stabilisation
energy [CFSE] of [Fe(CN)6]n–6, respectively,
are:
[Note : Ignore the pairing energy]
iCON Education HYD, 79930 92826, 73309 72826JEE Main 2020 (Online) 8th January Evening Slot
The correct order of the calculated spin-only
magnetic moments of complexs (A) to (D) is:
(A) Ni(CO)4
(B) [Ni(H2O)6]Cl2
(C) Na2[Ni(CN)4]
(D) PdCl2(PPh3)2
A.
(C) < (D) < (B) < (A)
B.
(C) $ \approx $ (D) < (B) < (A)
C.
(A) $ \approx $ (C) $ \approx $ (D) < (B)
D.
(A) $ \approx $ (C) < (B) $ \approx $ (D)
Correct Answer: C
Explanation:
(A) Ni(CO)4
Ni = 3d84s2
CO is strong field ligand. So pairing of elections happens.
$ \therefore $ Number of unpaired electrons = 0
$ \therefore $ $\mu $spin = 0
(B) [Ni(H2O)6]Cl2
Ni+2 = 3d84s0
H2O is weak field ligand. So no pairing of electrons happens.