Consider the empirical formula . According to Werner's experimental evidence, which of the following — Coordination Compounds Chemistry Question

💡 Solution & Explanation

Cobalt(III) consistently exhibits a coordination number (secondary valency) of 6. For $CoCl_3 \cdot 4NH_3$, the 4 $NH_3$ molecules and 2 of the $Cl^-$ ions must be inside the coordination sphere to satisfy this, leaving 1 $Cl^-$ outside. Thus, the formula is $[Co(NH_3)_4Cl_2]Cl$. This yields 1 mole of $AgCl$ per mole of complex (A is correct), produces 2 moles of ions ($[Co(NH_3)_4Cl_2]^+$ and $Cl^-$) (B is correct), and the structure is correct (C is correct). Only 2 chloride ions satisfy the secondary valency, not all 3 (D is incorrect).