The pair of compounds having the same general formula.

Options

A.
B.
C.
D.

Answer

To determine which pairs of compounds have the same general formula, we need to calculate the degree of unsaturation for each compound. The degree of unsaturation can be calculated by counting the number of double bonds, triple bonds, and rings in the structure. Each double bond or ring contributes one degree of unsaturation, while each triple bond contributes two degrees of unsaturation.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- We will analyze the given compounds one by one to determine their degree of unsaturation.

2. **Calculate Degree of Unsaturation for the First Pair**:
- **Compound A**: Benzene (C6H6)
- Benzene has 3 double bonds (due to its aromatic structure) and 1 ring.
- Degree of unsaturation = 3 (from double bonds) + 1 (from the ring) = 4.
- **Compound B**: Another compound (assumed to be similar to benzene)
- If it also has 3 double bonds and 1 ring, it will also have a degree of unsaturation of 4.
- **Conclusion**: Both compounds have the same degree of unsaturation (4), thus they have the same general formula: CnHn.

3. **Calculate Degree of Unsaturation for the Second Pair**:
- **Compound C**: A compound with 2 rings.
- Degree of unsaturation = 2 (from 2 rings).
- **Compound D**: Another compound with 1 double bond and 1 ring.
- Degree of unsaturation = 1 (from double bond) + 1 (from the ring) = 2.
- **Conclusion**: Both compounds have the same degree of unsaturation (2), thus they have the same general formula: CnH2n-2.

4. **Calculate Degree of Unsaturation for the Third Pair**:
- **Compound E**: A compound with 1 double bond and 1 ring.
- Degree of unsaturation = 1 (from double bond) + 1 (from the ring) = 2.
- **Compound F**: A compound with 2 double bonds.
- Degree of unsaturation = 2 (from 2 double bonds).
- **Conclusion**: Both compounds have different degrees of unsaturation (2 and 1), thus they do not have the same general formula.

5. **Calculate Degree of Unsaturation for the Fourth Pair**:
- **Compound G**: Benzene (C6H6)
- Degree of unsaturation = 4 (as calculated previously).
- **Compound H**: A compound with 4 triple bonds.
- Degree of unsaturation = 4 (from 4 triple bonds).
- **Conclusion**: Both compounds have the same degree of unsaturation (4), thus they have the same general formula: CnH2n-6.

### Final Summary:
- The first pair (Benzene and a similar compound) has the same general formula: CnHn.
- The second pair (Compound with 2 rings and Compound with 1 double bond and 1 ring) has the same general formula: CnH2n-2.
- The third pair does not have the same general formula.
- The fourth pair (Benzene and a compound with 4 triple bonds) has the same general formula: CnH2n-6.