Identify the correct relationship:

Options

A. In `[Cu(NH_(3))_(4)]^(2+)` complex Hybrization of `Cu=dsp^(2)`
B. `Fe(CO)_(x)` where `x` generally 5
C. `Zn^(2+)` complexes with `sp^(3)d^(2)` hybridization are diamagnetic in nature
D. `Cr^(3+)` complexes are paramagnetic in nature

Explanation

To solve the question "Identify the correct relationship," we will analyze each option provided in the video transcript step by step.

### Step 1: Analyze Option A - Cu(NH3)4^2+
1. **Identify the oxidation state of copper (Cu)**: In the complex Cu(NH3)4^2+, the charge of the complex is +2. Since NH3 is a neutral ligand, the oxidation state of Cu must be +2.
2. **Determine the electronic configuration of Cu**: The atomic number of copper (Cu) is 29. Its electronic configuration in the neutral state is [Ar] 4s^1 3d^10. In the +2 oxidation state, it loses two electrons (from 4s and 3d), resulting in the configuration [Ar] 3d^9.
3. **Determine the hybridization**: Since there are four NH3 ligands, the hybridization of Cu in this complex is Dsp^2 (one d orbital, one s orbital, and two p orbitals are involved).
4. **Conclusion for Option A**: The statement is correct.

### Step 2: Analyze Option B - Fe(CO)x
1. **Determine the effective atomic number (EAN)**: The EAN is calculated using the formula: EAN = Atomic number (Z) - Oxidation state (x) + 2y (where y is the number of ligands).
2. **Find the atomic number of iron (Fe)**: The atomic number of Fe is 26.
3. **Assume oxidation state**: For neutral carbonyl complexes, the oxidation state of Fe is 0.
4. **Calculate EAN**: Set up the equation: 26 - 0 + 2y = 36. Solving gives us y = 5.
5. **Conclusion for Option B**: The statement is correct.

### Step 3: Analyze Option C - Zn2+ complexes with sp3d2 hybridization
1. **Determine the electronic configuration of Zn**: The atomic number of Zn is 30, with a configuration of [Ar] 4s^2 3d^10. In the +2 oxidation state, it becomes [Ar] 3d^10.
2. **Determine the hybridization**: The hybridization sp^3d^2 indicates the use of six orbitals, but since all 3d orbitals are filled and there are no unpaired electrons, the complex is diamagnetic.
3. **Conclusion for Option C**: The statement is correct.

### Step 4: Analyze Option D - Cr3+ complexes
1. **Determine the electronic configuration of Cr**: The atomic number of Cr is 24, with a configuration of [Ar] 4s^1 3d^5. In the +3 oxidation state, it becomes [Ar] 3d^3 (losing one 4s and two 3d electrons).
2. **Check for unpaired electrons**: The 3d^3 configuration indicates there are three unpaired electrons.
3. **Conclusion for Option D**: The statement is correct.

### Final Conclusion
All options A, B, C, and D are correct.