Hybridization in Coordination Compounds and Molecules

❓ Question

The number of species from the following that are involved in:

$$sp^3d^2$$

hybridization is:

$$[Co(NH_3)_6]^{3+}, \ SF_6, \ [CrF_6]^{3-}, \ [CoF_6]^{3-}, \ [Mn(CN)_6]^{3-}, \ [MnCl_6]^{3-}$$

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🖼 Question Image

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✍️ Short Explanation

This problem is based on:

👉 Hybridization in coordination compounds
👉 Strong field and weak field ligands
👉 Inner orbital vs outer orbital complexes.

Main idea:

$$\boxed{ sp^3d^2 }$$

means:

✔ Outer orbital octahedral complex

while

$$\boxed{ d^2sp^3 }$$

means:

✔ Inner orbital octahedral complex

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🔷 Step 1 — Analyse $[Co(NH_3)_6]^{3+}$ 💯

Oxidation state:

$$Co^{3+}$$

Configuration:

$$3d^6$$

$NH_3$ is sufficiently strong ligand with $Co^{3+}$.

Pairing occurs.

Hybridization:

$$\boxed{ d^2sp^3 }$$

(inner orbital)

So NOT counted.

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🔷 Step 2 — Analyse $SF_6$

Sulfur expands octet.

Geometry:

$$\boxed{ sp^3d^2 }$$

Counted ✔

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🔷 Step 3 — Analyse $[CrF_6]^{3-}$

Oxidation state:

$$Cr^{3+}$$

Configuration:

$$3d^3$$

For $d^3$, two vacant $3d$ orbitals are not available after arrangement.

Thus outer orbital complex forms.

Hybridization:

$$\boxed{ sp^3d^2 }$$

Counted ✔

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🔷 Step 4 — Analyse $[CoF_6]^{3-}$

Oxidation state:

$$Co^{3+}$$

Configuration:

$$3d^6$$

$F^-$ is weak field ligand.

No pairing.

Hence outer orbital complex:

$$\boxed{ sp^3d^2 }$$

Counted ✔

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🔷 Step 5 — Analyse $[Mn(CN)_6]^{3-}$

Oxidation state:

$$Mn^{3+}$$

Configuration:

$$3d^4$$

$CN^-$is strong field ligand.

Pairing occurs.

Hybridization:

$$\boxed{ d^2sp^3 }$$

Not counted.

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🔷 Step 6 — Analyse $[MnCl_6]^{3-}$

Oxidation state:

$$Mn^{3+}$$

Configuration:

$$3d^4$$

$Cl^-$is weak field ligand.

No pairing.

Outer orbital complex:

$$\boxed{ sp^3d^2 }$$

Counted ✔

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🔷 Step 7 — Total Species with $sp^3d^2$

Counted species:

✔ $SF_6$

✔ $[CrF_6]^{3-}$

✔ $[CoF_6]^{3-}$

✔ $[MnCl_6]^{3-}$

Total:

$$\boxed{4}$$

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🔷 Step 8 — JEE Trap Alert 🚨

❌ $sp^3d^2$ and $d^2sp^3$ confuse kar dena

❌ Strong field vs weak field ligand bhool jaana

❌ $Co^{3+}$ complexes ka pairing effect ignore kar dena

Remember:

$$\boxed{ \text{Weak field ligand} \Rightarrow sp^3d^2 }$$

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✅ Final Answer

$$\boxed{{\displaystyle \mathrm{4}}}$$

(Option 4)

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