Explain how to solve this question. How to find secondary valancy of these compounds? And how to find coordination number from complex?
Dear student,
Secondary valency refers to the coordination number of a particular complex compound, or in other words it refers to the number of ligands that are directly attached to the central metal atom or ion.
In the first compound,
The moles of AgCl precipitated are two, this means that the two Cl attached must be outside of coordination sphere because the coordination sphere is difficult to break and if the two Cl were inside it cannot give precipitate with AgNO3.
Hence the two Cl must be outside which tell us that the Pd atom is attached to 4 NH3 ligands and hence the coordination number is 4 and secondary valency is 4.
In the 2nd compound,
The two Cl must be outside the coordination sphere so as to give the precipitate with AgNO3. Hence the 6 H2O groups must be inside the coordination sphere directly attached with Ni to give a coordination number of six and secondary valency as 6.
In the 3rd compound,
AgCl precipitate is not observed, hence all the Cl must be inside the coordination sphere which gives a coordination number of 6 and secondary valency also as 6.
In the 4th compound,
1 mole precipitate means 1 Cl must be outside the coordination sphere and two Cl and four NH3 must be inside the coordination sphere to give coordination number as 6 and secondary valency as 6.
In 5th compound,
No precipitate means both Cl and NH3 must be inside the coordination sphere which gives coordination number as 4 and secondary valency also as 6.
Hope this helps,
Regards
Secondary valency refers to the coordination number of a particular complex compound, or in other words it refers to the number of ligands that are directly attached to the central metal atom or ion.
In the first compound,
The moles of AgCl precipitated are two, this means that the two Cl attached must be outside of coordination sphere because the coordination sphere is difficult to break and if the two Cl were inside it cannot give precipitate with AgNO3.
Hence the two Cl must be outside which tell us that the Pd atom is attached to 4 NH3 ligands and hence the coordination number is 4 and secondary valency is 4.
In the 2nd compound,
The two Cl must be outside the coordination sphere so as to give the precipitate with AgNO3. Hence the 6 H2O groups must be inside the coordination sphere directly attached with Ni to give a coordination number of six and secondary valency as 6.
In the 3rd compound,
AgCl precipitate is not observed, hence all the Cl must be inside the coordination sphere which gives a coordination number of 6 and secondary valency also as 6.
In the 4th compound,
1 mole precipitate means 1 Cl must be outside the coordination sphere and two Cl and four NH3 must be inside the coordination sphere to give coordination number as 6 and secondary valency as 6.
In 5th compound,
No precipitate means both Cl and NH3 must be inside the coordination sphere which gives coordination number as 4 and secondary valency also as 6.
Hope this helps,
Regards