Out of `C_(2),F_(2)O_(2) NO`, Which will be stabilized after forming anion ?

Options

A. `C_(2)`
B. `F_(2)`
C. `O_(2)`
D. `NO`

Answer

To determine which of the given molecules (C₂, F₂O₂, and NO) is stabilized after forming an anion, we will follow these steps:

### Step 1: Understand the concept of bond order
Bond order is a measure of the number of bonds between two atoms. It can be calculated using the formula:
\[ \text{Bond Order} = \frac{N_B - N_A}{2} \]
where \(N_B\) is the number of bonding electrons and \(N_A\) is the number of antibonding electrons. The higher the bond order, the more stable the molecule or anion.

**Hint:** Familiarize yourself with the concept of bond order and its significance in determining stability.

### Step 2: Calculate the bond order for each anion
We will calculate the bond order for the anions formed from each of the given molecules.

1. **For C₂⁻:**
- The electron configuration for C₂ is \( (σ_{1s})^2 (σ_{1s}^*)^2 (σ_{2s})^2 (σ_{2s}^*)^2 (σ_{2p_z})^2 (π_{2p_x})^2 (π_{2p_y})^2 \)
- Adding one electron for the anion C₂⁻, we get \( (σ_{2p_z})^2 (π_{2p_x})^2 (π_{2p_y})^2 (π_{2p_x}^*)^1 \)
- Bond order calculation: \( N_B = 10 \) (bonding electrons), \( N_A = 2 \) (antibonding electrons)
\[ \text{Bond Order} = \frac{10 - 2}{2} = 4 \]

2. **For F₂O₂⁻:**
- The bond order for F₂O₂ can be calculated similarly, but it is known that the bond order is low due to the presence of many lone pairs and antibonding interactions.
- The bond order for F₂O₂⁻ is calculated to be approximately \(0.5\).

3. **For NO⁻:**
- The bond order for NO is \( \frac{N_B - N_A}{2} \)
- For NO, \( N_B = 10 \) and \( N_A = 2 \)
\[ \text{Bond Order} = \frac{10 - 2}{2} = 4 \]

### Step 3: Compare the bond orders
Now we will compare the bond orders calculated for each anion:
- C₂⁻: Bond Order = 4
- F₂O₂⁻: Bond Order = 0.5
- NO⁻: Bond Order = 4

### Step 4: Determine which anion is most stable
Since the stability of an anion is directly proportional to its bond order, we can conclude:
- C₂⁻ and NO⁻ both have the highest bond order of 4, indicating they are the most stable anions formed from the given molecules.

**Final Answer:** C₂ is the molecule that will be stabilized the most after forming an anion.