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NEET CHEMISTRYCoordination CompoundsMedium

Question

Urea reacts with water to form A which will decompose to form B. B when passed through Cu2+(aq)Cu^{2+}(aq), deep blue colour solution C is formed. What is the formula of C from the following?

A

[Cu(NH3)4]2+[Cu(NH_3)_4]^{2+}

B

Cu(OH)2Cu(OH)_2

C

CuCO3⋅Cu(OH)2CuCO_3 \cdot Cu(OH)_2

D

CuSO4CuSO_4

Step-by-Step Solution

  1. Formation of B: Urea (NH2CONH2NH_2CONH_2) on hydrolysis with water forms ammonium carbonate (A), which is unstable and decomposes to give ammonia (NH3NH_3), water, and carbon dioxide. NH2CONH2+2H2O→(NH4)2CO3→2NH3+H2O+CO2NH_2CONH_2 + 2H_2O \rightarrow (NH_4)_2CO_3 \rightarrow 2NH_3 + H_2O + CO_2 Thus, compound B is Ammonia (NH3NH_3).
  2. Formation of C: When ammonia solution is added to aqueous copper(II) ions (Cu2+Cu^{2+}), the water ligands are replaced by ammonia ligands (which are stronger field ligands in the spectrochemical series relative to water, though closer in strength, ammonia forms stable amine complexes). This results in the formation of a deep blue complex ion, tetraamminecopper(II). Cu2+(aq)+4NH3(aq)→[Cu(NH3)4]2+(aq) (Deep Blue)Cu^{2+}(aq) + 4NH_3(aq) \rightarrow [Cu(NH_3)_4]^{2+}(aq) \text{ (Deep Blue)} This complex is explicitly mentioned as an example of a coordination compound in the NCERT text .

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from Coordination Compounds. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYCoordination Compoundsreactsdecomposepassedthroughcolour

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The complex, $[\text{Pt}(\text{Py})(\text{NH}_3)\text{BrCl}]$ will have how many geometrical isomers?

A.4
B.0
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Among the given complexes, the complex having the highest paramagnetic behaviour is: (At. No. Ti = 22, Cr = 24, Co = 27, Zn = 30)

A.$[Zn(NH_3)_6]^{2+}$
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Mg is present in:

A.Chlorophyll
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The complexes $[\text{Co}(\text{NH}_3)_6][\text{Cr}(\text{CN})_6]$ and $[\text{Cr}(\text{NH}_3)_6][\text{Co}(\text{CN})_6]$ are examples of:

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The coordination compound that gives the maximum number of isomers is:

A.$[Co(NH_3)_4Cl_2]$
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$[Cu(NH_3)_4]^{2+}$ reacts with $HNO_3$ in excess of water and gives:

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CFSE (in the octahedral field) will be maximum in: (Atomic number Co = 27)

A.[Co(H₂O)₆]³⁺
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The IUPAC name of the following complex is: $[Ag(H_2O)_2][Ag(CN)_2]$

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