Assertion :- Oxidation number of `Ni` in `[Ni(CO)_(4)]` is zero. Reason :- Nickel is bonded to neutral ligand, carbonyl.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are False.

Answer

To solve the problem regarding the oxidation number of nickel in the complex \([Ni(CO)_{4}]\), we will follow these steps:

### Step 1: Understand the Complex
The complex given is \([Ni(CO)_{4}]\), where \(Ni\) is nickel and \(CO\) is carbon monoxide, which acts as a ligand.

### Step 2: Identify the Nature of the Ligand
Carbon monoxide (CO) is a neutral ligand. This means it does not contribute any charge to the overall oxidation state of the complex.

### Step 3: Set Up the Equation for Oxidation Number
Let the oxidation number of nickel (Ni) be \(x\). Since there are four carbonyl ligands and each has an oxidation state of 0 (because they are neutral), we can express the total charge of the complex as follows:

\[ x + 4(0) = 0 \]

### Step 4: Solve for \(x\)
From the equation, we have:

\[ x = 0 \]

This indicates that the oxidation number of nickel in the complex \([Ni(CO)_{4}]\) is 0.

### Step 5: Conclusion
The assertion states that the oxidation number of Ni in \([Ni(CO)_{4}]\) is zero, which we have confirmed to be true. The reason given is that nickel is bonded to a neutral ligand (carbonyl), which is also true. Therefore, both the assertion and the reason are correct, and the reason correctly explains the assertion.

### Final Answer
Both the assertion and reason are correct, and the reason is the correct explanation of the assertion.

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