Which of the following is crotonaldehyde ?

Options

A.
B.
C.
D.

Explanation

To determine which of the given options is crotonaldehyde, we can follow these steps:

### Step 1: Understand the structure of crotonaldehyde
Crotonaldehyde is a chemical compound with the molecular formula \( \text{C}_4\text{H}_8\text{O} \) and its structural formula is \( \text{CH}_3\text{CH}=\text{CHCHO} \). This indicates that it has a double bond between the second and third carbon atoms and an aldehyde functional group (-CHO) at the end.

### Step 2: Analyze the options provided
We need to compare the options given in the question with the structural formula of crotonaldehyde. The correct structure must have:
- 4 carbon atoms
- 8 hydrogen atoms
- 1 oxygen atom
- A double bond between the second and third carbon atoms.

### Step 3: Identify the correct option
Assuming the options are:
1. \( \text{CH}_3\text{CH}_2\text{CHO} \) (butyric aldehyde)
2. \( \text{CH}_3\text{CH}=\text{CHCHO} \) (crotonaldehyde)
3. \( \text{CH}_3\text{C}=\text{C}\text{CHO} \) (isomer of crotonaldehyde)
4. \( \text{C}_4\text{H}_{10}\text{O} \) (butanol)

From the options:
- The second option \( \text{CH}_3\text{CH}=\text{CHCHO} \) matches the structure of crotonaldehyde.

### Step 4: Conclusion
The correct answer is option B: \( \text{CH}_3\text{CH}=\text{CHCHO} \).

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