Which is expected to react most readily with bromine

Options

A. `C_(3)H_(6)`
B. `C_(2)H_(2)`
C. `C_(4)H_(10)`
D. `C_(2)H_(4)`

Answer

To determine which hydrocarbon is expected to react most readily with bromine, we need to analyze the structures and types of hydrocarbons given in the question. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Hydrocarbons
We have four hydrocarbons to analyze:
1. C3H6
2. C2H2
3. C4H10
4. C2H4

### Step 2: Determine the Type of Each Hydrocarbon
- **C3H6**: This has the formula CnH2n, which indicates it is an alkene (contains a double bond).
- **C2H2**: This has the formula CnH2n-2, indicating it is an alkyne (contains a triple bond).
- **C4H10**: This has the formula CnH2n+2, indicating it is an alkane (contains only single bonds).
- **C2H4**: This also has the formula CnH2n, indicating it is another alkene.

### Step 3: Reactivity Order of Hydrocarbons
The reactivity of hydrocarbons with bromine can be ranked as follows:
1. Alkenes (double bonds) > Alkynes (triple bonds) > Alkanes (single bonds)

### Step 4: Analyze the Alkenes
Among the identified alkenes (C3H6 and C2H4), we need to determine which one is more reactive. The reactivity of alkenes increases with the degree of substitution:
- **C3H6**: This alkene can be represented as propene (CH3-CH=CH2), which is a monosubstituted alkene.
- **C2H4**: This alkene is ethylene (CH2=CH2), which is an unsubstituted alkene.

Since propene (C3H6) is more substituted than ethylene (C2H4), it is expected to be more reactive.

### Step 5: Conclusion
Based on the analysis, the hydrocarbon that is expected to react most readily with bromine is **C3H6 (propene)**, due to its status as a more substituted alkene.

### Final Answer
**C3H6 (propene)** is expected to react most readily with bromine.

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