How many structural alkenes of formula `C_(2)FClBrI` are possible:

Explanation

To determine the number of structural alkenes with the formula \( C_2FClBrI \), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Alkene Structure**:
- Alkenes are hydrocarbons that contain at least one carbon-carbon double bond. For the formula \( C_2FClBrI \), we have two carbon atoms that will be connected by a double bond: \( C=C \).

2. **List the Atoms**:
- The given formula contains four different substituents: fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).

3. **Fix One Substituent**:
- To find the structural isomers, we can fix one of the substituents in a specific position. Let's fix chlorine (Cl) at one of the carbon atoms.

4. **Arrange the Remaining Substituents**:
- With Cl fixed, we can arrange the remaining three substituents (F, Br, I) around the two carbon atoms. The possible arrangements are:
- Cl on Carbon 1, and the other three substituents on Carbon 2.
- We can rotate F, Br, and I around Carbon 2 while keeping Cl fixed.

5. **Count the Arrangements**:
- The arrangements for the substituents on Carbon 2 can be done in different ways:
- Cl - F - Br - I
- Cl - F - I - Br
- Cl - Br - F - I
- Cl - Br - I - F
- Cl - I - F - Br
- Cl - I - Br - F

However, since we are looking for structural isomers, we need to ensure that each arrangement leads to a distinct structure.

6. **Identify Unique Structures**:
- After considering the fixed position of Cl, we can find that there are three unique structural isomers:
1. Cl on Carbon 1, F on Carbon 2, Br on Carbon 2, I on Carbon 2.
2. Cl on Carbon 1, Br on Carbon 2, F on Carbon 2, I on Carbon 2.
3. Cl on Carbon 1, I on Carbon 2, F on Carbon 2, Br on Carbon 2.

7. **Conclusion**:
- The total number of structural alkenes possible with the formula \( C_2FClBrI \) is **3**.