Question #44688

A highly precise thermogravimetric analysis is performed on $2.5000 \text{ g}$ of a pure, hydrated coordination complex of an unknown first-row transition metal $M$. The complex has the empirical formula $K_a[M(C_2O_4)_b] \cdot xH_2O$. Upon heating to $150^\circ\text{C}$ to constant weight, the sample loses exactly $0.2727 \text{ g}$ of water. The anhydrous residue is then exhaustively reduced, yielding exactly $0.2976 \text{ g}$ of pure metal $M$. Given the exact atomic masses (in $\text{g/mol}$): $\text{K} = 39.10$, $\text{C} = 12.01$, $\text{O} = 16.00$, $\text{H} = 1.008$, and assuming the ligands act as strong field ligands in this specific geometry, what is the spin-only magnetic moment ($\mu$) and the hybridization of the central metal ion $M$ in the original complex? \newline \textit{(Note: Use exact atomic masses for first-row transition metals to identify $M$ and its oxidation state. Common rounded masses: $\text{Cr}=52, \text{Mn}=55, \text{Fe}=56, \text{Co}=59, \text{Ni}=59, \text{Cu}=64$)}