Which of the following is non-conducting?

$A$ solution contains $2.675 \ g$ of $CoCl_3 \cdot 6NH_3$ $(M = 267.5 \ g/mol)$. When passed through a cation exchanger,the chloride ions liberated are treated with excess $AgNO_3$ to yield $4.78 \ g$ of $AgCl$ $(M = 143.5 \ g/mol)$. What is the formula of the coordination compound?

$5.33 \text{ g}$ of $CrCl_3 \cdot 6H_2O$, which is a $1:3$ electrolyte, is dissolved in water and passed through a cation exchanger. The chloride ions in the eluted solution, on treatment with $AgNO_3$, result in $8.61 \text{ g}$ of $AgCl$. The ratio of moles of complex reacted and moles of $AgCl$ formed is . . . . . . $\times 10^{-2}$. (Nearest integer) [Molar mass in $\text{g mol}^{-1}$: $Cr = 52, Ag = 108, Cl = 35.5, H = 1, O = 16$]

The stability constants for complexes formed by a metal ion $(M^{2+})$ with ligands $NH_3$,$CN^-$,$H_2O$,and $en$ are $10^{11}$,$10^{27}$,$10^{15}$,and $10^8$ respectively. Based on these values,which of the following is correct?

$CO$ is a stronger ligand than $Cl^{-}$ because:

The stepwise formation of $[Cu(NH_{3})_{4}]^{2+}$ is given below:
$Cu^{2+} + NH_{3} \rightleftharpoons [Cu(NH_{3})]^{2+} \quad K_{1}$
$[Cu(NH_{3})]^{2+} + NH_{3} \rightleftharpoons [Cu(NH_{3})_{2}]^{2+} \quad K_{2}$
$[Cu(NH_{3})_{2}]^{2+} + NH_{3} \rightleftharpoons [Cu(NH_{3})_{3}]^{2+} \quad K_{3}$
$[Cu(NH_{3})_{3}]^{2+} + NH_{3} \rightleftharpoons [Cu(NH_{3})_{4}]^{2+} \quad K_{4}$
The values of stability constants $K_{1}, K_{2}, K_{3}$ and $K_{4}$ are $10^{4}, 1.58 \times 10^{3}, 5 \times 10^{2}$ and $10^{2}$ respectively. The overall equilibrium constant for dissociation of $[Cu(NH_{3})_{4}]^{2+}$ is $x \times 10^{-12}$. The value of $x$ is ...............
(Rounded off to the nearest integer)