Select the correct order of first ionisation potential

Options

A. `O_(2)^(2+)gtO_(2)`
B. `O_(2)^(2+)ltO_(2)`
C. `O_(2)~~O_(2)^(+)`
D. None of these

Answer

To determine the correct order of first ionization potential (IP) for the given species O2^2+ and O2, we need to analyze the electronic configuration and stability of each species.

### Step 1: Understand Ionization Potential
First ionization potential is defined as the energy required to remove the outermost electron from a neutral atom or molecule. The higher the stability of the atom or molecule, the higher the ionization potential.

**Hint:** Remember that stability affects how easily an electron can be removed.

### Step 2: Analyze O2^2+
O2^2+ has a total of 14 electrons (16 from O2 minus 2 due to the +2 charge). In this case, all the electrons are paired, making O2^2+ diamagnetic. The paired electrons contribute to the stability of the molecule.

**Hint:** Check the total number of electrons and their pairing to assess stability.

### Step 3: Analyze O2
O2 has 16 electrons. In this molecule, there are unpaired electrons in the anti-bonding orbitals, which makes O2 paramagnetic. The presence of unpaired electrons generally indicates that the molecule is less stable compared to its diamagnetic counterpart.

**Hint:** Identify unpaired electrons as they indicate lower stability.

### Step 4: Compare Stability and Ionization Potential
Since O2^2+ is more stable (due to all electrons being paired), it will have a higher first ionization potential compared to O2, which is less stable due to the presence of unpaired electrons.

**Hint:** Stability is inversely related to ionization potential; more stable means higher IP.

### Step 5: Conclusion
Based on the analysis, the correct order of first ionization potential is:
O2^2+ > O2

**Final Answer:** O2^2+ has a greater first ionization potential than O2.