Which of the following statement is correct regarding following species?
(i) `Cl overset(E.A.)to Cl^(-)`
(ii) `Cl^(-) overset(I.E.)to Cl`
(iii) `Cl overset (I.E.) to Cl^+`
(iv) `Cl^(+) overset(I.E.)to Cl^(2+)`

Options

A. |I.E. of process (ii)|=|E.A. of process (i)|
B. |I.E. of process (iii)|=|I.E. of process (ii)|
C. |I.E. of process (iv)|=|E.A. of process (i)|
D. |I.E. of process (iv)|=|I.E. of process (iii)|

Answer

To determine which statement is correct regarding the given species, we need to analyze each process step by step.

### Step 1: Understanding the Processes
1. **Process (i)**: \( Cl + e^- \rightarrow Cl^- \) (Electron Affinity)
- This process involves adding an electron to chlorine to form a chloride ion. It releases energy, making it exothermic.

2. **Process (ii)**: \( Cl^- \rightarrow Cl + e^- \) (Ionization Energy)
- This process involves removing an electron from the chloride ion to form a neutral chlorine atom. It requires energy, making it endothermic.

3. **Process (iii)**: \( Cl \rightarrow Cl^+ + e^- \) (Ionization Energy)
- This process involves removing an electron from a neutral chlorine atom to form a positively charged ion. It also requires energy, making it endothermic.

4. **Process (iv)**: \( Cl^+ \rightarrow Cl^{2+} + e^- \) (Ionization Energy)
- This process involves removing an electron from a positively charged chlorine ion to form a doubly charged ion. It requires even more energy due to the increased nuclear charge.

### Step 2: Analyzing the Relationships
- **Electron Affinity and Ionization Energy**:
- The magnitude of the energy change in process (i) (electron affinity) is equal to the magnitude of the energy required in process (ii) (ionization energy) but with opposite signs. Thus, we can say:
\[ \text{EA (i)} = -\text{IE (ii)} \]
- Therefore, the first statement is correct: **Electron Affinity of process (i) is equal to Ionization Energy of process (ii)**.

### Step 3: Evaluating Other Statements
- **Process (ii) vs. Process (iii)**:
- The ionization energy required to remove an electron from \( Cl^- \) (process ii) is less than that required to remove an electron from \( Cl \) (process iii) because \( Cl^- \) is more stable than \( Cl \). Thus, statement (ii) is incorrect.

- **Process (iii) vs. Process (iv)**:
- The ionization energy required to remove an electron from \( Cl^+ \) (process iv) is greater than that required to remove an electron from \( Cl \) (process iii) because \( Cl^+ \) has a higher nuclear charge and is smaller in size. Thus, statement (iv) is incorrect.

- **Comparing Process (iv) and Process (i)**:
- The ionization energy in process (iv) is not equal to the electron affinity in process (i) since they involve different species and processes. Thus, statement (iii) is incorrect.

### Conclusion
The only correct statement is:
- **(i)**: \( Cl + e^- \rightarrow Cl^- \) (Electron Affinity) is equal to \( Cl^- \rightarrow Cl + e^- \) (Ionization Energy).

### Final Answer
The correct statement is: **(i)** \( Cl + e^- \rightarrow Cl^- \) is equal to \( Cl^- \rightarrow Cl + e^- \).

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