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Coordination Compounds · Question 20

JEE Main 2026 (Online) 24th January Morning ShiftMCQMedium📈 Topic in 10% papers+4−1
1

Consider a mixture 'X' which is made by dissolving 0.4 mol of [Co(NH3)5SO4]Br and 0.4 mol of [Co(NH3)5Br]SO4 in water to make 4 L of solution. When 2 L of mixture 'X' is allowed to react with excess of AgNO3, it forms precipitate 'Y'. The rest 2 L of mixture 'X' reacts with excess BaCl2 to form precipitate 'Z'. Which of the following statements is CORRECT?

  1. 0.1 mol of 'Y' is formed.
  2. 0.4 mol of 'Z' is formed.
  3. 0.2 mol of 'Z' is formed.
  4. 'Y' is BaSO4 and 'Z' is AgBr.

Answer

(3) 0.2 mol of 'Z' is formed.

Solution

Each 2 L portion contains 0.2 mol of each complex.

Ions in solution:

[Co(NH3)5SO4]Br [Co(NH3)5SO4]+ + Br- (only Br- is free)

[Co(NH3)5Br]SO4 [Co(NH3)5Br]2+ + SO42- (only SO42- is free)

With excess AgNO3: Ag+ + Br- AgBr Y = AgBr, 0.2 mol

With excess BaCl2: Ba2+ + SO42- BaSO4 Z = BaSO4, 0.2 mol

(Ligands inside the coordination sphere are not precipitated.)

0.2 mol of 'Z' is formed.

Answer: (3)

JEE Main 2026 (Online) 24th January Morning Shift

Keep practising — Coordination Compounds

2

The wavelengths of light absorbed for the following complexes are in the order (I) [Co(NH3)6]3+ ; (II) [Co(H2O)6]3+ ; (III) [Co(CN)6]3- ; (IV) [Co(NH3)5(H2O)]3+ ; (V) [CoF6]3-

  1. III < IV < I < II < V
  2. III < I < IV < V < II
  3. III < I < IV < II < V
  4. III < I < II < IV < V
JEE Main 2026 (Online) 24th January Evening Shift
3

A chromium complex with a formula CrCl3 6H2O has a spin only magnetic moment value of 3.87 BM and its solution conductivity corresponds to 1 : 2 electrolyte. 2.75 g of the complex solution was initially passed through a cation exchanger. The solution obtained after the process was reacted with excess of AgNO3. The amount of AgCl formed in the above process is g. (Nearest integer) [Given: Molar mass in g mol-1 Cr : 52, Cl : 35.5, Ag : 108, O : 16, H : 1]

JEE Main 2026 (Online) 24th January Evening Shift
4

The statements that are incorrect about the nickel(II) complex of dimethylglyoxime are : Choose the correct answer from the options given below :

  1. C and E Only
  2. A, D and B Only
  3. B, C and E Only
  4. C and D Only
JEE Main 2026 (Online) 23rd January Morning Shift
5

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

  1. Both Statement I and Statement II are false
  2. Both Statement I and Statement II are true
  3. Statement I is false but Statement II is true
  4. Statement I is true but Statement II is false
JEE Main 2026 (Online) 23rd January Morning Shift
6

The crystal field stabilisation energy of [Co(oxalate)3]3- complex is 'n' times that of the [Cr(oxalate)3]3- complex. Here 'n' is . (Assume o P)

JEE Main 2026 (Online) 23rd January Morning Shift
7

Identify the CORRECT set of details from the following : Choose the correct answer from the options given below :

  1. C & D Only
  2. A, C & E Only
  3. A, B, C, D & E
  4. A, B & D Only
JEE Main 2026 (Online) 23rd January Evening Shift
8

Total number of unpaired electrons present in the central metal atoms/ions of [Ni(CO)4], [NiCl4]2-, [PtCl2(NH3)2], [Ni(CN)4]2- and [Pt(CN)4]2- is .

JEE Main 2026 (Online) 23rd January Evening Shift
9

Consider the transition metal ions Mn3+, Cr3+, Fe3+ and Co3+ and all form low spin octahedral complexes. The correct decreasing order of unpaired electrons in their respective d-orbitals of the complexes is

  1. Cr3+ > Mn3+ > Fe3+ > Co3+
  2. Mn3+ > Fe3+ > Co3+ > Cr3+
  3. Fe3+ > Co3+ > Mn3+ > Cr3+
  4. Cr3+ > Fe3+ > Co3+ > Mn3+
JEE Main 2026 (Online) 22nd January Morning Shift
10

A first row transition metal (M) does not liberate H2 gas from dilute HCl. 1 mol of aqueous solution of MSO4 is treated with excess of aqueous KCN and then H2S(g) is passed through the solution. The amount of MS (metal sulphide) formed from the above reaction is mol.

  1. 1
  2. 2
  3. 0
  4. 3
JEE Main 2026 (Online) 22nd January Morning Shift
11

[Ni(PPh3)2Cl2] is a paramagnetic complex. Identify the INCORRECT statements about this complex. Choose the correct answer from the options given below :

  1. C and D Only
  2. A, B and D Only
  3. C, D and E Only
  4. A and B Only
JEE Main 2026 (Online) 22nd January Evening Shift

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