HOTS (Higher Order Thinking Skills) 1. Why do we not use coal gas as a cooking fuel? 2. Why does petroleum float on water? 3. Why do different types of coal have different compositions? 4. Can we prepare coal and petroleum in a laboratory? 5. Suggest some methods to reduce LPG consumption at home?
HOTS (Higher Order Thinking Skills) 1. Why do we not use coal gas as a cooking fuel? 2. Why does petroleum float on water? 3. Why do different types of coal have different compositions? 4. Can we prepare coal and petroleum in a laboratory? 5. Suggest some methods to reduce LPG consumption at home?
The Correct Answer and Explanation is:
Here are the Higher Order Thinking Skills (HOTS) questions with correct answers and a 300-word explanation:
1. Why do we not use coal gas as a cooking fuel?
Answer: Coal gas is toxic, highly flammable, and polluting, making it unsafe and unsuitable for domestic cooking.
2. Why does petroleum float on water?
Answer: Petroleum is less dense than water and is immiscible, so it floats on the water’s surface.
3. Why do different types of coal have different compositions?
Answer: Different types of coal form under varying pressure, temperature, and time conditions, resulting in different carbon content and impurities.
4. Can we prepare coal and petroleum in a laboratory?
Answer: No, we cannot prepare coal and petroleum in a laboratory as their formation takes millions of years under natural geological processes.
5. Suggest some methods to reduce LPG consumption at home.
Answer:
- Use pressure cookers to cook food faster.
- Keep burner flames blue (not yellow) for efficiency.
- Cook with lids on pots.
- Cut vegetables finely to reduce cooking time.
- Turn off the gas as soon as cooking is done.
Explanation
Coal gas, though historically used for lighting and heating, is now avoided in homes due to its harmful effects. It contains carbon monoxide, a poisonous gas, and can lead to fatal accidents if inhaled. Additionally, coal gas is more polluting compared to cleaner alternatives like LPG (liquefied petroleum gas), which burns with minimal soot and pollutants.
Petroleum floats on water because of its lower density and immiscibility with water. Since oil is less dense than water and does not dissolve in it, it remains on the surface. This property causes major environmental hazards during oil spills, as it spreads across water bodies and harms marine life.
Coal forms from plant matter buried under layers of earth over millions of years. The pressure, heat, and time vary across locations, leading to the formation of different coal types—peat, lignite, bituminous, and anthracite—each with distinct carbon contents and properties.
Despite technological advances, we cannot artificially recreate coal or petroleum in a lab. These fossil fuels require complex geological processes over millions of years. Thus, they are considered non-renewable resources, and their conservation is crucial.
To reduce LPG consumption at home, energy-efficient cooking methods can be used. Cooking with lids on pots retains heat and reduces cooking time. Using pressure cookers, minimizing the size of vegetables for quicker cooking, and maintaining appliances for optimal flame efficiency help save gas. These practices not only reduce fuel bills but also contribute to energy conservation and environmental protection.
