Q.
On the basis of the following observations made with aqueous solutions, find the number of complexes in which the secondary valence of the metal ion is $6$
Formula
Moles of $AgCl$ precipitated per mole of the compound with excess $AgNO_3$
i
$PdCl_2. 4NH_3$
2
ii
$NiCl_2.6H_2O$
2
iii
$PtCl_4\cdot 2HCl$
0
iv
$CoCl_3 . 4NH_3$
1
v
$PtCl_4 \cdot 2NH_3$
0
| Formula | Moles of $AgCl$ precipitated per mole of the compound with excess $AgNO_3$ | |
|---|---|---|
| i | $PdCl_2. 4NH_3$ | 2 |
| ii | $NiCl_2.6H_2O$ | 2 |
| iii | $PtCl_4\cdot 2HCl$ | 0 |
| iv | $CoCl_3 . 4NH_3$ | 1 |
| v | $PtCl_4 \cdot 2NH_3$ | 0 |
NTA AbhyasNTA Abhyas 2022
Solution:
The secondary valence is equal to the coordination number of the metal ion. Number of moles of $AgCl$ indicates that the $Cl^{-}$ ion is not attached to the central metal ion.
Formula
Moles of $AgCl$ precipitated per mole of the compound with excess $AgNO_3$
i
$Pt(NH_3)_4Cl_2$$
4
ii
$NiH_2O_6Cl_2$
6
iii
$PtCl_4(HCl)_2$
6
iv
$CoCl_3 (NH_3)_4Cl$
6
v
$PtCl_4 (NH_3)_2$
6
| Formula | Moles of $AgCl$ precipitated per mole of the compound with excess $AgNO_3$ | |
|---|---|---|
| i | $Pt(NH_3)_4Cl_2$$ | 4 |
| ii | $NiH_2O_6Cl_2$ | 6 |
| iii | $PtCl_4(HCl)_2$ | 6 |
| iv | $CoCl_3 (NH_3)_4Cl$ | 6 |
| v | $PtCl_4 (NH_3)_2$ | 6 |