Give the structures of the alkene `(C_4H_8)` which adds on HBr in the presence and in the absence of peroxide to give the same product , `C_4H_9Br`

Explanation

To solve the problem of identifying the structures of the alkene \(C_4H_8\) that adds HBr in both the presence and absence of peroxide to yield the same product \(C_4H_9Br\), we can follow these steps:

### Step 1: Determine the Possible Structures of \(C_4H_8\)
The molecular formula \(C_4H_8\) indicates that there is one degree of unsaturation (double bond). The possible structures for alkenes with four carbon atoms include:
1. 1-butene (CH2=CH-CH2-CH3)
2. 2-butene (CH3-CH=CH-CH3)
3. Cyclobutane (not considered here as it does not fit the alkene definition)

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