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

Options

A. butan-2-al
B. butan-1-al
C. butan-1-one
D. butan-2-one

Answer

To find the IUPAC name of the compound `CH₃CH₂COCH₃`, we will follow the steps for naming organic compounds systematically.

### Step-by-Step Solution:

1. **Identify the Structure**: The given compound can be represented as:
```
CH₃ - CH₂ - C(=O) - CH₃
```
This shows that we have a carbon chain with a carbonyl (C=O) group.

2. **Determine the Longest Carbon Chain**: We need to find the longest continuous chain of carbon atoms. In this case, the longest chain consists of 4 carbon atoms:
```
CH₃ - CH₂ - C - CH₃
```

3. **Identify the Functional Group**: The functional group present in this compound is a ketone (since the carbonyl group is located between two carbon atoms).

4. **Number the Carbon Chain**: We will number the carbon chain starting from the end closest to the carbonyl group to give the functional group the lowest possible number. Numbering from the left:
```
1 2 3 4
CH₃ - CH₂ - C(=O) - CH₃
```
Here, the carbonyl group is on carbon 2.

5. **Assign the Name Based on the Numbering**: The base name for a 4-carbon alkane is "butane". Since we have a ketone, we will use the suffix "-one". The position of the carbonyl group is on carbon 2, so we will include that in the name.

6. **Final IUPAC Name**: Combining all the information, the IUPAC name of the compound is:
**Butan-2-one**.

### Final Answer:
The IUPAC name of `CH₃CH₂COCH₃` is **Butan-2-one**.