Yes, solving previous years' papers of UPSC Chemistry optional can help in improving conceptual understanding. Here's how:

1. Familiarity with Exam Pattern:
- Solving previous years' papers gives you an insight into the exam pattern and the type of questions asked in the UPSC Chemistry optional paper.
- It helps you understand the distribution of marks across different topics and the level of difficulty.

2. Identifying Important Topics:
- Going through previous years' papers helps you identify the important topics that are frequently asked in the exam.
- It allows you to prioritize your study and focus more on the areas that have higher weightage.

3. Understanding Question Framing:
- By solving previous years' papers, you get a good idea of how questions are framed in the UPSC Chemistry optional paper.
- You can understand the language and structure of questions, which can help you in better comprehending and answering them effectively.

4. Testing and Reinforcing Concepts:
- Solving previous years' papers allows you to test your understanding of various concepts in Chemistry.
- It helps in reinforcing your knowledge by applying the concepts to real exam-like questions.
- You can identify areas where you need more practice and work on strengthening those concepts.

5. Time Management:
- Practicing previous years' papers helps in improving your time management skills.
- It familiarizes you with the time constraints of the exam and helps you in strategizing your approach to solve questions within the given time frame.

6. Boosting Confidence:
- Regularly solving previous years' papers builds confidence in your preparation.
- It gives you a sense of familiarity with the exam and reduces exam anxiety.
- With increased confidence, you can perform better and make fewer mistakes during the actual UPSC Chemistry optional paper.

Therefore, solving previous years' papers of UPSC Chemistry optional is an effective strategy to improve conceptual understanding, identify important topics, understand question framing, test and reinforce concepts, manage time effectively, and boost confidence for the exam.