From the following pair, select the stronger base:
pyridine or pyrrole

Answer

To determine which compound is the stronger base between pyridine and pyrrole, we need to analyze the structures and the availability of the lone pair of electrons on the nitrogen atom in each compound.

### Step-by-Step Solution:

1. **Identify the Structures**:
- Pyridine is a six-membered aromatic ring containing one nitrogen atom. The nitrogen has a lone pair of electrons that is not involved in resonance with the aromatic system.
- Pyrrole is a five-membered aromatic ring that contains one nitrogen atom. In pyrrole, the lone pair of electrons on the nitrogen is involved in resonance with the π-electrons of the ring.

2. **Understand Basicity**:
- Basicity is the ability of a compound to accept protons (H⁺ ions). A stronger base has a lone pair of electrons that is readily available to bond with protons.
- If the lone pair is delocalized (involved in resonance), it is less available for bonding with protons, thus decreasing basicity.

3. **Analyze Pyrrole**:
- In pyrrole, the lone pair of electrons on the nitrogen atom participates in resonance with the π-system of the ring. This delocalization makes the lone pair less available for protonation, leading to lower basicity.

4. **Analyze Pyridine**:
- In pyridine, the lone pair of electrons on the nitrogen is localized and not involved in resonance with the ring. This means that the lone pair is readily available to accept a proton, making pyridine a stronger base compared to pyrrole.

5. **Conclusion**:
- Based on the above analysis, we conclude that pyridine is the stronger base compared to pyrrole because its lone pair of electrons is not delocalized and is readily available for protonation.

### Final Answer:
**Pyridine is the stronger base.**