Alicyclic compounds are

Options

A. (A) Aromatic compounds
B. (B) Aliphatic cyclic compounds
C. (C) Heterocyclic compounds
D. (D) None of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Definition**:
- Alicyclic compounds are defined as compounds that are both aliphatic and cyclic. This means they contain carbon atoms arranged in a ring structure (cyclic) while also maintaining the characteristics of aliphatic compounds, which are typically open-chain structures.

2. **Identifying Aliphatic Compounds**:
- Aliphatic compounds are those that consist of carbon and hydrogen atoms arranged in straight or branched chains. Examples include ethane (C2H6) and propane (C3H8). These compounds do not have a ring structure.

3. **Identifying Cyclic Compounds**:
- Cyclic compounds are those that have their carbon atoms arranged in a closed loop or ring. Examples include cyclopropane (C3H6) and cyclobutane (C4H8). These compounds can be saturated or unsaturated.

4. **Combining the Concepts**:
- An alicyclic compound combines the features of both aliphatic and cyclic compounds. For example, cyclopropane is a ring structure (cyclic) but is made up of carbon atoms in a way that resembles aliphatic compounds.

5. **Differentiating from Other Types of Compounds**:
- It is important to differentiate alicyclic compounds from aromatic compounds, which have a different structure and properties due to the presence of delocalized pi electrons (following Huckel's rule, 4n + 2 rule).
- Heterocyclic compounds are another category that includes atoms other than carbon in the ring structure, such as nitrogen, oxygen, or sulfur.

6. **Conclusion**:
- Based on the definitions and examples provided, the correct identification of alicyclic compounds is that they are aliphatic cyclic compounds.

**Final Answer**: Alicyclic compounds are aliphatic cyclic compounds.

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