Which of the following is incorrectly matched :

Options

A. `{:("Common name",,,,"IUPAC name"),((1)"Croton aldehyde",,,,:But-2-enal):}`
B. `{:("Common name",,,,"IUPAC name"),((2)"Cinnamic acid",,,,:"3-Phenyl prop-2-enoic acid"):}`
C. `{:("Common name",,,,"IUPAC name"),((3)"Lactic acid",,,,:"2-Hydroxy propanoic acid"):}`
D. `{:("Common name",,,,"IUPAC name"),("Acrylonitrile" ,,,,:"But-2-ene nitrile"):}`

Answer

To determine which of the following pairs is incorrectly matched, we will analyze each compound's common name and its corresponding IUPAC name step by step.

### Step 1: Analyze Crotonaldehyde
- **Common Name**: Crotonaldehyde
- **Structure**: CH3CH=CHCHO
- **IUPAC Name**:
- The longest carbon chain contains 4 carbons.
- The double bond is between the second and third carbon.
- The aldehyde group is at the end of the chain.
- Therefore, the IUPAC name is But-2-enal.

**Conclusion**: This matches correctly.

### Step 2: Analyze Cinnamic Acid
- **Common Name**: Cinnamic Acid
- **Structure**: C6H5CH=CHCOOH
- **IUPAC Name**:
- The main functional group is the carboxylic acid (COOH).
- The longest chain has 3 carbons (including the carbon in the phenyl ring).
- The double bond is between the second and third carbon.
- Therefore, the IUPAC name is 3-phenylprop-2-enoic acid.

**Conclusion**: This matches correctly.

### Step 3: Analyze Lactic Acid
- **Common Name**: Lactic Acid
- **Structure**: CH3CH(OH)COOH
- **IUPAC Name**:
- The longest chain has 3 carbons.
- The hydroxyl group (OH) is on the second carbon.
- The carboxylic acid group is at the end.
- Therefore, the IUPAC name is 2-hydroxypropanoic acid.

**Conclusion**: This matches correctly.

### Step 4: Analyze Acrylonitrile
- **Common Name**: Acrylonitrile
- **Structure**: CH2=CH-C≡N
- **IUPAC Name**:
- The longest chain has 3 carbons.
- The double bond is between the first and second carbon.
- The nitrile group (C≡N) is at the end of the chain.
- Therefore, the IUPAC name is 2-propenenitrile.

**Conclusion**: The common name "Acrylonitrile" is incorrectly matched with the IUPAC name "But-2-ene nitrile" as it should be "Prop-2-enenitrile".

### Final Answer
The incorrectly matched pair is **Acrylonitrile**.

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