Man-Made Materials — Set 3
Chemistry · मानव निर्मित सामग्री · Questions 21–30 of 50
Which process is used to make soaps from fats or oils and sodium hydroxide?
Correct Answer: C. Saponification
• **Saponification** = Saponification is the chemical reaction where an ester is heated with an alkali to produce soap and glycerol. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Polymerization; B: Fermentation; D: Hydrogenation
Detergents are better than soaps for laundry in hard water because?
Correct Answer: C. They do not form insoluble scum
• **They do not form insoluble scum** = Soaps react with calcium and magnesium ions in hard water to form an insoluble precipitate called scum. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: They are cheaper; B: They are biodegradable; D: They are made from natural oils
What is the chemical name for the explosive commonly known as TNT?
Correct Answer: C. Trinitrotoluene
• **Trinitrotoluene** = Trinitrotoluene is a stable explosive that requires a detonator to explode. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Tri-nitro-triazine; B: Trinitrophenol; D: Nitroglycerin
Which chemical is often used as a 'fixing agent' in the manufacturing of ink?
Correct Answer: A. Tannic acid
• **Tannic acid** = Tannic acid reacts with iron salts to produce a permanent black color in traditional inks. • (Contextual detail from explanation) • 💡 Wrong-option analysis: B: Acetic acid; C: Ammonia; D: Alcohol
Which substance is used to provide a red color to fireworks?
Correct Answer: A. Strontium salts
• **Strontium salts** = Strontium salts emit a characteristic deep red light when they are heated in a flame. • (Contextual detail from explanation) • 💡 Wrong-option analysis: B: Sodium salts; C: Copper salts; D: Barium salts
The chemical used for the 'artificial ripening' of green fruits is?
Correct Answer: D. Ethylene
• **Ethylene** = Ethylene is a natural plant hormone that triggers the ripening process in fruits. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Methane; B: Carbon dioxide; C: Ethane
Which of the following is a bio-polymer produced by living organisms?
Correct Answer: A. Starch
• **Starch** = Starch is a natural polymer made of glucose units produced by plants for energy storage. • (Contextual detail from explanation) • 💡 Wrong-option analysis: B: PVC; C: Terylene; D: Nylon
Which synthetic chemical is most commonly added as a preservative in packaged foods like soft drinks and fruit juices to inhibit microbial growth?
Correct Answer: A. Sodium Benzoate
• **Sodium Benzoate** = Sodium benzoate (C6H5COONa) is the most widely used synthetic food preservative, particularly in acidic foods like soft drinks, fruit juices, and pickles. • **5** — Sodium benzoate (C6H5COONa) is the most widely used synthetic food preservati... • 💡 Wrong-option analysis: B: Sodium Chloride; C: Acetic Acid; D: Citric Acid
What is the main component of 'LPG' used as a domestic fuel?
Correct Answer: B. Propane and Butane
• **Propane and Butane** = Liquefied Petroleum Gas consists primarily of butane and propane which are easily liquefied under pressure. • (Contextual detail from explanation) • 💡 Wrong-option analysis: A: Ethane; C: Hydrogen; D: Methane
Which material is used for the coating of 'matchstick' heads?
Correct Answer: A. Antimony trisulfide and Potassium chlorate
• **Antimony trisulfide and Potassium chlorate** = The correct answer is 'Antimony trisulfide and Potassium chlorate'. • (Contextual detail from explanation) • 💡 Wrong-option analysis: B: Red phosphorus; C: Sulfur; D: White phosphorus