Correct IUPAC name for `H_(3)C - underset(C_(2)H_(5))underset(|)(CH) - underset(C_(2)H_(5))underset(|)(CH) - CH_(3)` is......

Options

A. 2-ethyl-3-methylpentane
B. 3, 4-dimethylhexane
C. 2-sec-butylbutane
D. 2, 3-dimethylbutane

Explanation

To determine the correct IUPAC name for the compound \( H_3C - C_2H_5 - |(CH) - C_2H_5 - |(CH) - CH_3 \), we will follow these steps:

### Step 1: Draw the Structure
First, we need to draw the structure of the compound based on the provided formula. The structure can be represented as follows:

```
CH3
|
CH2-CH
|
CH-CH2-CH3
```

### Step 2: Identify the Longest Carbon Chain
Next, we need to identify the longest carbon chain in the structure. By examining the structure, we can see that the longest continuous chain of carbon atoms consists of 6 carbon atoms.

### Step 3: Number the Carbon Atoms
We will number the carbon atoms in the longest chain starting from one end. The numbering will be as follows:

```
1 2 3 4 5 6
CH3-CH2-CH-CH-CH2-CH3
```

### Step 4: Identify and Name the Substituents
Now, we need to identify the substituents attached to the main chain. In this case, we have:
- A methyl group (–CH3) at carbon 3.
- Another methyl group (–CH3) at carbon 4.

### Step 5: Write the IUPAC Name
According to IUPAC nomenclature, we will list the substituents in alphabetical order along with their positions. Since we have two methyl groups, we will use the prefix "dimethyl". The main chain has 6 carbon atoms, which corresponds to "hexane". Therefore, the name will be:

**3,4-Dimethylhexane**

### Final Answer
The correct IUPAC name for the compound is **3,4-dimethylhexane**.

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