### Core Logic A homoleptic complex is one in which the central metal atom/ion is bound to only one kind of donor group (ligand). A heteroleptic complex is one in which the central metal atom/ion is bound to more than one kind of donor group. ### Step 1: Analyze Options (1) [Ni(CN)_4]^2-$[Ni(CN)_4]^{2-}$: Only one type of ligand (CN^-$CN^-$). Homoleptic. (2) [Ni(NH_3)_2Cl_2]$[Ni(NH_3)_2Cl_2]$: Two types of ligands (NH_3$NH_3$ and Cl^-$Cl^-$). Heteroleptic. (3) [Fe(NH_3)_4Cl_2]^+$[Fe(NH_3)_4Cl_2]^+$: Two types of ligands. Heteroleptic. (4) [Co(NH_3)_4Cl_2]^+$[Co(NH_3)_4Cl_2]^+$: Two types of ligands. Heteroleptic. ### Pattern Recognition Homo = same, leptic = ligands. Look for the formula bracket containing only one symbol type after the central metal. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Chemistry: Coordination Compounds

### Related Formula textOxidation State of Mn Evaluation: 2(+1) + x + 4(-2) = 0$\text{Oxidation State of Mn Evaluation: } 2(+1) + x + 4(-2) = 0$ ### Core Logic Solving for x$x$: 2 + x - 8 = 0 implies x = +6$2 + x - 8 = 0 \implies x = +6$ Since the complex is anionic, the metal name ends with the suffix '-ate', making it 'manganate(VI)'. The ligands are oxygen atoms, designated systematically as 'tetraoxido' or 'tetraoxo' according to newer recommendations. ### Step 1: Assembly Combining parts systematically yields the correct IUPAC string: Potassium tetraoxidomanganate(VI). ### Pattern Recognition Anionic metal centers must include the trailing '-ate' modifier followed immediately by their absolute Roman oxidation state indicators. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Chemistry: Coordination Compounds

### Step 1: Evaluation of P=[FeF_6]^3-$P=[FeF_6]^{3-}$ textFe^3+ rightarrow 3textd^5$\text{Fe}^{3+} \rightarrow 3\text{d}^5$ Since textF^-$\text{F}^-$ is a weak field ligand, no pairing occurs. Number of unpaired electrons (n$n$) = 5. mu = sqrt5(5+2) = sqrt35text BM$\mu = \sqrt{5(5+2)} = \sqrt{35}\text{ BM}$ ### Step 2: Evaluation of Q=[V(H_2O)_6]^2+$Q=[V(H_2O)_6]^{2+}$ textV^2+ rightarrow 3textd^3$\text{V}^{2+} \rightarrow 3\text{d}^3$ Number of unpaired electrons (n$n$) = 3. mu = sqrt3(3+2) = sqrt15text BM$\mu = \sqrt{3(3+2)} = \sqrt{15}\text{ BM}$ ### Step 3: Evaluation of R=[Fe(H_2O)_6]^2+$R=[Fe(H_2O)_6]^{2+}$ textFe^2+ rightarrow 3textd^6$\text{Fe}^{2+} \rightarrow 3\text{d}^6$ Since textH_2textO$\text{H}_2\text{O}$ is a weak field ligand, configuration is textt_2textg^4 texte_textg^2$\text{t}_{2\text{g}}^4 \text{e}_{\text{g}}^2$. Number of unpaired electrons (n$n$) = 4. mu = sqrt4(4+2) = sqrt24text BM$\mu = \sqrt{4(4+2)} = \sqrt{24}\text{ BM}$ ### Step 4: Comparison Comparing values: mu(Q) < mu(R) < mu(P) implies Q < R < P$\mu(Q) < \mu(R) < \mu(P) \implies Q < R < P$ ### Pattern Recognition Count unpaired electrons strictly accounting for weak field vs strong field rules. Order scales monotonically with n$n$. ### Chapter Mix Class 12 Chemistry: Coordination Compounds

### Core Logic Let us identify the central metal atom/element present in each of the given coordination complexes or biological molecules: 1. **Ziegler-Natta catalyst**: Used for polymerization of alkenes. Its chemical composition involves TiCl_4$TiCl_4$ and (C_2H_5)_3Al$(C_2H_5)_3Al$. Hence, the transition metal present is Titanium (IV). 2. **Blood pigment (Haemoglobin)**: The oxygen-carrying metalloprotein in red blood cells. It contains an Iron (III) central atom coordinated to a porphyrin ring. 3. **Wilkinson's catalyst**: Used for the hydrogenation of alkenes. Its formula is [RhCl(PPh_3)_3]$[RhCl(PPh_3)_3]$, meaning it contains Rhodium (I). 4. **Vitamin B_12$B_{12}$ (Cyanocobalamin)**: A biologically important coordination compound containing Cobalt (II) at the center of a corrin ring. ### Step 1: Final Mapping Matching the elements: (A) Ziegler catalyst rightarrow$\rightarrow$ (IV) Titanium (B) Blood Pigment rightarrow$\rightarrow$ (III) Iron (C) Wilkinson catalyst rightarrow$\rightarrow$ (I) Rhodium (D) Vitamin B_12$B_{12}$ rightarrow$\rightarrow$ (II) Cobalt This strictly maps to sequence A-IV, B-III, C-I, D-II. ### Pattern Recognition Always memorize the central metal for famous catalysts and biomolecules: Chlorophyll (Mg), Haemoglobin (Fe), Vitamin B12 (Co), Wilkinson (Rh), Ziegler-Natta (Ti). ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Chemistry: Coordination Compounds Class 12 Chemistry: d and f Block Elements