An Overview of Ncert Books Class 12 Chemistry Chapter 16 Free Download
FAQs on Ncert Books Class 12 Chemistry Chapter 16 Free Download
1. What are the most important topics in 'Chemistry in Everyday Life' for the Class 12 Board exam?
For the CBSE 2025-26 exam, you should focus on these high-scoring areas:
- Classification of Drugs: Questions on analgesics, tranquillizers, antiseptics, and antibiotics are very common.
- Cleansing Agents: The difference between soaps and detergents, and the mechanism of cleansing action are frequently asked.
- Chemicals in Food: Be sure to study artificial sweetening agents and food preservatives.
2. What types of questions can be expected from this chapter in the board exams?
This chapter usually features short-answer questions. Expect 1-mark MCQs asking for an example of a specific drug (like an antacid), 2-mark questions asking for definitions (e.g., broad-spectrum antibiotics), and 3-mark questions that require you to explain a concept or differentiate between terms like antiseptic vs. disinfectant.
3. How should I answer a question on the difference between soaps and detergents to get full marks?
To score full marks, present your answer in a table format. Include at least three key points of difference, such as:
- Their chemical nature (salts of long-chain fatty acids vs. salts of long-chain sulphonic acids).
- Their action in hard water (soaps form scum, detergents do not).
- Their biodegradability (soaps are generally biodegradable, while some detergents are not).
4. Are chemical structures important to memorise from this chapter for the exam?
Yes, for certain key compounds. You should focus on the structures of common drugs like aspirin and paracetamol. Also, remember the basic structure of a soap and detergent molecule. You may not be asked to draw complex structures from scratch, but you might need to identify them or their functional groups.
5. What is a common mistake students make in questions about artificial sweeteners?
A frequent error is not remembering the specific use and limitations of each sweetener. For example, students often confuse Aspartame, which is unstable at cooking temperatures, with sweeteners like Sucralose, which is stable when heated. For full marks, always mention the name, its relative sweetness, and any specific conditions for its use.
6. Why is it important to specify whether an antibiotic is 'bactericidal' or 'bacteriostatic' in an answer?
It's crucial for scoring well because it shows a deeper level of understanding. A bactericidal antibiotic kills bacteria, while a bacteriostatic one only inhibits their growth. In an exam answer, just naming an antibiotic is not always enough. Mentioning its specific action (e.g., 'Penicillin is bactericidal') adds technical detail and can earn you a better score.
7. How can questions from this chapter test higher-order thinking skills (HOTS)?
HOTS questions from this chapter often involve reasoning or application. For example, a question might ask, 'Why should ranitidine not be taken with antacids?' or 'Why can a soap solution act as a mild disinfectant?'. These questions require you to connect the chemical properties of a substance to its real-world application or interaction.
8. What key terms must I include when explaining the cleansing action of soap?
To give a complete explanation of soap's cleansing action, you must use and briefly explain these key terms:
- Micelle formation: The sphere-like structure formed by soap molecules in water.
- Hydrophilic head: The water-attracting part of the soap molecule.
- Hydrophobic tail: The oil-attracting part of the soap molecule.
- Emulsification: The process where micelles trap oil and dirt, allowing it to be washed away.
