In `[Ni(NH_3)_4]SO_4`, the E.A.N. of `Ni` is

Options

A. (a) `34`
B. (b) `35`
C. (c) `36`
D. (d) `37`

Explanation

To find the Effective Atomic Number (EAN) of Nickel (Ni) in the coordination compound \([Ni(NH_3)_4]SO_4\), we can follow these steps:

### Step 1: Identify the Coordination Compound
The given compound is \([Ni(NH_3)_4]SO_4\). This indicates that Nickel is coordinated with four ammonia (NH₃) ligands.

### Step 2: Determine the Oxidation State of Nickel
To find the oxidation state of Nickel (Ni) in the complex, we can set up the following equation based on the overall charge of the complex:

Let the oxidation state of Ni be \(x\).

The charge contributed by the ammonia ligands (NH₃) is neutral (0), and the sulfate ion (SO₄) has a charge of -2. Thus, the overall charge of the complex ion \([Ni(NH_3)_4]^{2+}\) is +2.

The equation can be set up as:
\[ x + 4(0) = +2 \]
This simplifies to:
\[ x = +2 \]
So, the oxidation state of Ni is +2.

### Step 3: Calculate the EAN
The formula for Effective Atomic Number (EAN) is given by:
\[ \text{EAN} = \text{Atomic Number} - \text{Oxidation State} + 2 \times \text{Number of Ligands} \]

- The atomic number of Nickel (Ni) is 28.
- The oxidation state we found is +2.
- The number of ligands (NH₃) is 4.

Now, substituting these values into the EAN formula:
\[ \text{EAN} = 28 - 2 + 2 \times 4 \]
Calculating this step-by-step:
1. \(28 - 2 = 26\)
2. \(2 \times 4 = 8\)
3. \(26 + 8 = 34\)

Thus, the EAN of Nickel in \([Ni(NH_3)_4]SO_4\) is **34**.

### Final Answer
The EAN of Ni in \([Ni(NH_3)_4]SO_4\) is **34**.

---