We get a copper complex with ammonia having the formula [Cu(NH3)4]2+only in alkaline solution and not in acidic solution. It can be explained on the basis of the fact that :


Correct option is

In acidic solution, the protons forms  with NH3 molecules

Since the NH3 molecules form  ion in acidic solution, so NH3molecules are not available for formation of complex ion [Cu(NH3)4]2+and thus the complex is not formed.




Which method can be used to distinguish

[Co(NH3)6][Cr(NO2)6] and [Cr(NH3)6][Co(NO2)6]


Select the complex that involves outer hybridization of central metal ion.


A complex containing Mn2+ and Br ion was found to have a magnetic moment of 5.92 BM. The probable formula and geometry of the complex is most likely to be :



A solution of ‘X’ containing 0.02 mole of ‘X’ per litre is mixed with another solution, a solution of ‘Y’ containing 0.02 mole of ‘Y’ per litre. 

     1 L of mixture solution + AgBO3 → ‘A’ ↓ 

     1 L of mixture solution + Excess BaCl2 → ‘B’↓  

If  ‘X’ is [Co(NH3)5SO4]Br, and    

     ‘Y’ is [Co(NH3)5Br]SO4,

then the number of moles of ‘A’ and ‘B’ obtained are, respectively


The splitting of degenerate d-orbitals in the formation of certain complex was observed as shown below


This type of splitting of d-orbitals occurs in the formation of


Which is not a π-acceptor ligand?


A complex of a certain metal ion has a magnetic moment of 4.90 B.M. Another complex of the same metal ion in the same oxidation state has a zero magnetic moment. Which of the following could be the central metal ion in the two complexes?


Which of the following is most acidic aqua ion?


Select the complex in which secondary valency is satisfied before the primary valency. 




The molecular formula of both ‘A’ and ‘B’ is same. 

A’ can be converted to B be boiling in dil. HCl. 

A’ on reaction with oxalic acid yields a complex having the formula Ni(NH3)2(C2O4) but ‘B’ does not. 

From the above information we can say that