There are two compounds A and B of molecular formula `C_(9)H_(18)O_(3)`. A has higher boiling point than B. What are the possible structures of A and B?

Options

A.
B.
C.
D.

Explanation

To determine the possible structures of compounds A and B with the molecular formula \( C_9H_{18}O_3 \) where compound A has a higher boiling point than compound B, we can analyze the structures based on the presence of functional groups and their ability to form hydrogen bonds.

### Step 1: Identify the Functional Groups
- The molecular formula \( C_9H_{18}O_3 \) suggests that both compounds could contain alcohol (-OH) groups and ether (R-O-R') groups.
- Alcohols can form hydrogen bonds, which typically lead to higher boiling points compared to ethers, which cannot form hydrogen bonds as effectively.

### Step 2: Analyze the Boiling Point
- Since compound A has a higher boiling point than compound B, we can infer that A likely contains more alcohol groups than B. This is because the presence of more hydroxyl (-OH) groups increases the potential for hydrogen bonding, leading to a higher boiling point.

### Step 3: Propose Possible Structures
- **Compound A**: To have a higher boiling point, we can propose that compound A has three hydroxyl groups (making it a triol). A possible structure could be:
- Structure of A:
- 1,2,3-Propanetriol (Glycerol) with additional carbon chains to fulfill the molecular formula.

- **Compound B**: In contrast, compound B can be an ether with fewer hydroxyl groups. A possible structure could be:
- Structure of B:
- A tri-ether structure, where three ether groups are present, leading to lower hydrogen bonding capability.

### Step 4: Validate the Structures
- We can validate that the proposed structures fit the molecular formula \( C_9H_{18}O_3 \):
- For compound A (triol), we can have:
- \( C_3H_8O_3 \) (Glycerol) plus additional carbons to reach \( C_9 \).
- For compound B (tri-ether), we can have:
- \( C_9H_{18}O_3 \) structured as three ether groups.

### Conclusion
- Therefore, the possible structures are:
- **Compound A**: A triol with three -OH groups.
- **Compound B**: A tri-ether with no -OH groups.

### Summary of Structures
- **A**: Triol (e.g., 1,2,3-propanetriol with additional carbon chains)
- **B**: Tri-ether (e.g., three ether groups)