`C_(3)H_(8)+CI_(2)overset(Light)toC_(3)H_(7)CI+HCI` is an example of which of the following types of reactions ?

Options

A. Substitution
B. Elimination
C. Addition
D. Rearrangement

Answer

To determine the type of reaction represented by the equation \( C_3H_8 + Cl_2 \overset{Light}{\rightarrow} C_3H_7Cl + HCl \), we can follow these steps:

### Step 1: Identify the Reactants and Products
The reactants in this reaction are propane (\( C_3H_8 \)) and chlorine gas (\( Cl_2 \)). The products are propyl chloride (\( C_3H_7Cl \)) and hydrochloric acid (\( HCl \)).

### Step 2: Analyze the Reaction Conditions
The reaction occurs in the presence of light, which indicates that it is likely a photochemical reaction. Light can provide the energy needed to break chemical bonds.

### Step 3: Understand the Mechanism
In this reaction, the chlorine molecule undergoes homolytic cleavage due to the energy provided by light, forming two chlorine radicals (\( Cl \cdot \)). These radicals are highly reactive and can initiate a chain reaction.

### Step 4: Identify the Type of Reaction
The chlorine radical will abstract a hydrogen atom from propane, forming a propyl radical (\( C_3H_7 \cdot \)). This radical then reacts with another chlorine radical to form propyl chloride and release another hydrogen radical, which combines with a chlorine radical to form hydrochloric acid.

### Step 5: Conclusion
Since the reaction involves the replacement of a hydrogen atom in propane with a chlorine atom, it is classified as a **substitution reaction**. Specifically, this is an example of a free radical substitution reaction.

### Final Answer
The reaction \( C_3H_8 + Cl_2 \overset{Light}{\rightarrow} C_3H_7Cl + HCl \) is an example of a **substitution reaction**.

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