Secondary valency of Co is 6.Then how there could be one ionizable Cl - in the pic?
Q2: The ratio of moles of AgCl precipitated by adding AgN03to PdCl2.4NH3 and CoCl3.4NH3 respectively, is


Dear student,
The secondary valency is non ionisable and primary valency is ionisable. A secondary valency is not responsible for the charge on coordination sphere and only affects the oxidation number of central metal ion. As a matter of fact, since NH3 does not forms precipitate with any compound or ion, it is always written inside the coordination sphere. That means, In PdCl2.4NH3 the coordination number of Pd+2 is 4 hence all the four NH3 ligand must be included in coordination sphere which means 2 Cl-(ionisable) must be outside the sphere which will give 2 moles of AgCl precipitate.

Similarly, since the coordination number of Co+3 is 6, hence 4 NH3 and 2 Cl can be inside the coordination sphere and 1 Cl(ionisable) must be outside the coordination sphere which in turn will give one mole AgCl precipitate.

Hope it helps

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