Strategies to effectively answer questions requiring application of principles and laws in Paper I of UPSC Chemistry Optional subject:

1. Understand the question:
- Read the question carefully to grasp the requirements and identify the specific principle or law that needs to be applied.
- Pay attention to keywords such as "explain," "describe," "justify," or "compare," as they indicate the type of response expected.

2. Review and revise:
- Before attempting such questions, revise the fundamental principles and laws covered in the UPSC Chemistry Optional syllabus.
- Familiarize yourself with important equations, definitions, concepts, and their applications.
- Review relevant examples and practice problem-solving to enhance your understanding and application skills.

3. Break down the question:
- Break down the question into smaller parts or sub-questions to ensure a systematic and comprehensive approach.
- Identify the key components or variables involved in the problem and their relationships.

4. Plan your answer:
- Develop a clear and structured plan for answering the question.
- Outline the main points or arguments you will present to support your answer.
- Allocate appropriate time to each section or sub-question to ensure effective time management during the exam.

5. Apply principles and laws:
- Apply the relevant principles and laws to analyze the given information and solve the problem.
- Use appropriate equations, formulas, or relationships to derive the required solution.
- Clearly state the principles or laws you are applying and explain the reasoning behind your approach.

6. Provide supporting evidence:
- Support your answer with relevant examples, experimental evidence, or logical reasoning.
- Cite specific references to principles, laws, or scientific studies to strengthen your argument.

7. Use diagrams or illustrations:
- Utilize diagrams, graphs, or illustrations wherever applicable to enhance the clarity and visual appeal of your answer.
- Label the key components and provide a brief explanation or analysis of the diagram.

8. Use concise language:
- Express your answer in a clear, concise, and coherent manner.
- Avoid unnecessary jargon or excessive technical language.
- Use appropriate scientific terminology and symbols where required.

9. Review and proofread:
- Allocate some time at the end to review your answer and ensure its accuracy and coherence.
- Check for any grammatical errors, spelling mistakes, or missing information.
- Make necessary revisions if time permits.

By following these strategies, you can effectively answer questions that require the application of principles and laws in Paper I of UPSC Chemistry Optional subject. Remember to practice regularly and seek clarification on any doubts to strengthen your understanding and problem-solving skills.