When two free radicals collide

Options

A. termination of the free radical reaction results
B. they explode with the release of a large quantity of energy
C. ionization results
D. none of the above is possible

Explanation

To solve the question "When two free radicals collide," we can break down the process into three main steps: initiation, propagation, and termination. Here’s a step-by-step explanation:

### Step 1: Initiation
- **Description**: The process begins with the formation of free radicals. This can occur through various means such as heat, light, or chemical reactions. For example, when chlorine gas (Cl2) is exposed to light, it can dissociate into two chlorine radicals (Cl•).
- **Equation**: Cl2 → 2 Cl•

### Step 2: Propagation
- **Description**: Once free radicals are formed, they can react with other molecules. In this step, a chlorine radical can react with a methane molecule (CH4). This reaction leads to the formation of hydrochloric acid (HCl) and a methyl radical (CH3•).
- **Equation**: Cl• + CH4 → HCl + CH3•

- **Further Propagation**: The methyl radical can further react with another chlorine molecule, leading to the formation of chloromethane (CH3Cl) and regenerating another chlorine radical.
- **Equation**: CH3• + Cl2 → CH3Cl + Cl•

### Step 3: Termination
- **Description**: The reaction can continue as long as there are free radicals present. However, when two free radicals collide, they can combine to form a stable molecule, effectively terminating the radical chain reaction. For instance, two methyl radicals can combine to form ethane (C2H6).
- **Equation**: CH3• + CH3• → C2H6

### Conclusion
- When two free radicals collide, they can lead to the termination of the reaction by forming stable products. This is an important aspect of radical chemistry, as it indicates that the reaction can be controlled and will not continue indefinitely.

### Final Answer
When two free radicals collide, they can terminate the reaction by forming stable products.

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