IUPAC name of `CH_(3)CH_(2)CH_(2)COCH_(3)` is

Options

A. 2-pentanone
B. Pentan-2-one
C. pentanone-2
D. all the above

Answer

To determine the IUPAC name of the compound `CH₃CH₂CH₂COCH₃`, we will follow these steps:

### Step 1: Identify the longest carbon chain
The first step is to identify the longest continuous carbon chain in the molecule. In this case, the longest chain consists of 5 carbon atoms:

```
CH₃-CH₂-CH₂-C(=O)-CH₃
```

### Step 2: Identify the functional group
Next, we need to identify the functional group present in the molecule. The `CO` part indicates a ketone functional group, which is characterized by a carbonyl group (C=O) attached to two carbon atoms.

### Step 3: Number the carbon chain
We will number the carbon chain starting from the end closest to the functional group to give the ketone the lowest possible number. In this case, we can number the chain as follows:

1. C1: CH₃
2. C2: CH₂
3. C3: CH₂
4. C4: C(=O)
5. C5: CH₃

### Step 4: Assign the position of the functional group
The ketone group is located at carbon 2 (C2) of the chain.

### Step 5: Determine the base name and suffix
Since there are 5 carbon atoms in the longest chain, the base name is "pentane". The presence of a ketone functional group means we will use the suffix "-one".

### Step 6: Combine the information
Putting it all together, we have:
- The base name: pentane
- The position of the ketone: 2
- The suffix for the ketone: -one

Thus, the IUPAC name of the compound is **2-pentanone**.

### Final Answer:
The IUPAC name of `CH₃CH₂CH₂COCH₃` is **2-pentanone**.

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