order of reactivity of `C_2H_6, C_2H_4` and `C_2H_2` is

Options

A. `C_2H_6 gt C_2H_4 gt C_2H_2`
B. `C_2H_2 gt C_2H_6 gt C_2H_4`
C. `C_2 H_2 gt C_2H_4 gt C_2H_6`
D. All are equally reactive

Explanation

To determine the order of reactivity of the compounds \( C_2H_6 \), \( C_2H_4 \), and \( C_2H_2 \), we will analyze the structure and type of each compound:

1. **Identify the Compounds**:
- \( C_2H_6 \) is ethane, which is an alkane.
- \( C_2H_4 \) is ethylene, which is an alkene.
- \( C_2H_2 \) is acetylene, which is an alkyne.

2. **Understand the Reactivity of Hydrocarbons**:
- Alkanes (like ethane) are saturated hydrocarbons and generally have the lowest reactivity due to the presence of only single bonds.
- Alkenes (like ethylene) contain at least one double bond, which makes them more reactive than alkanes because the double bond can participate in addition reactions.
- Alkynes (like acetylene) contain at least one triple bond, which makes them even more reactive than alkenes due to the presence of two pi bonds that can participate in reactions.

3. **Order the Reactivity**:
- Since alkanes are the least reactive, we place \( C_2H6 \) (ethane) at the lowest position in the reactivity order.
- Next, \( C_2H4 \) (ethylene) is more reactive than \( C_2H6 \) because of its double bond.
- Finally, \( C_2H2 \) (acetylene) is the most reactive due to its triple bond.

4. **Final Order of Reactivity**:
- The order of reactivity from least to most reactive is:
\[ C_2H6 < C_2H4 < C_2H2 \]

**Final Answer**: The order of reactivity is \( C_2H6 < C_2H4 < C_2H2 \).

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