Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. Which among the following is the most abundant organic compound in nature?
[A] Glucose
[B] Fructose
[C] Sucrose
[D] Cellulose
Show Answer
Correct Answer: D [Cellulose]
Notes:
Cellulose is the most abundant organic compound in nature. It is the main constituent of plant fiber. Plants contain on average 33% cellulose, and cotton is the purest form at 90%. Chitin is the second most abundant organic compound in nature.
2. An Jewellery was left exposed to the atmosphere for some time and it becomes coated with green carbonate. The Jewellery is made up of which of the following?
[A] Copper
[B] Silver
[C] Zinc
[D] Gold
Show Answer
Correct Answer: A [Copper]
Notes:
The correct answer is Copper. When copper jewelry is exposed to air and moisture, it reacts with carbon dioxide and water, forming copper carbonate, which appears as a green patina (often called verdigris). This process is known as oxidation. Unlike copper, silver and gold do not typically form green coatings. silver may tarnish to a black color due to silver sulfide formation, while gold is highly resistant to corrosion and tarnishing.
3. Which among the following suspension in water is often called milk of magnesia because of its milk-like appearance?
[A] Magnesium Carbonate
[B] Magnesium Hydroxide
[C] Magnesium Lactate
[D] Magnesium Oxide
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Correct Answer: B [Magnesium Hydroxide]
Notes:
Magnesium Hydroxide in water is often called milk of magnesia because of its milk-like appearance. Magnesium hydroxide is the inorganic compound and occurs in nature as the mineral brucite.
4. Cassiterite is a primary ore of which of the following elements?
[A] Iron
[B] Zinc
[C] Copper
[D] Tin
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Correct Answer: D [Tin]
Notes:
Cassiterite is a mineral that is a significant ore of tin. It is also known as tin oxide. Although rare, its key characteristic is its high specific gravity that makes it easy to separate it from other materials. Tin, which is extracted from Cassiterite, is commonly used in making alloys, punches, and cutting tools.
5. What is Carbamide?
[A] A Pesticide
[B] A Fertilizer
[C] A Textile Dye
[D] An Explosive
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Correct Answer: B [A Fertilizer]
Notes:
Carbamide is another name of Urea, an organic compound with chemical formula CO(NH2)2. This name indicates that Urea is an amide in which two –NH2 groups are joined by a carbonyl (C=O) functional group.
6. The Potassium graphite and Calcium Graphite can be mostly used as which among the following?
[A] Moderators
[B] Semiconductors
[C] Superconductors
[D] Lubricants
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Correct Answer: C [Superconductors]
Notes:
Potassium graphite and calcium graphite are primarily used as superconductors. Superconductors are materials that can conduct electricity without resistance when cooled below a certain temperature. Graphite, particularly when doped with potassium or calcium, exhibits enhanced superconducting properties. Notably, the discovery of high-temperature superconductors in the 1980s revolutionized the field, leading to applications in magnetic levitation and advanced electronic devices.
7. Which of the following chemicals is also known as "sweet oil of vitriol"?
[A] Diethyl ether
[B] Aluminium sulphate
[C] Sulphuric acid
[D] Iron(III) sulphate
Show Answer
Correct Answer: A [ Diethyl ether]
Notes:
Diethyl ether is a colourless, highly volatile & flammable organic compound. It was earlier used for anaesthesia but after the development of non-flammable drugs, its uses as anaesthetic has been reduced.
8. Which of the following is an example of colloidal solution?
[A] Milk
[B] Fog
[C] Smoke
[D] All of the above
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Correct Answer: D [All of the above]
Notes:
Milk, Fog, Smoke, Cheese, Clouds, Mist, Shaving cream, Butter, Jelly etc. are some of the examples of colloidal solution.
9. Which of the following is a correct statement about minerals and ores?
[A] All minerals are ores
[B] All ores are minerals
[C] Minerals are the native form in which various metals exist
[D] Ores are usually used to extract metals economically
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Correct Answer: A [All minerals are ores]
Notes:
All ores are minerals but all minerals are not ores. Minerals are the native form in which various metals exist and ores are those minerals which are used to extract metals economically.
10. Which of the following is / are correct statement(s) about Gypsum?
[A] It’s a mineral composed of calcium sulfate dihydrate
[B] It is a soft mineral
[C] It is commonly added to saline soils to reduce salinity
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Gypsum is a mineral composed of calcium sulfate dihydrate. It’s a soft mineral and colorless to white in color. It is commonly added to saline soils to reduce salinity and also used in wallboard (drywall) and plaster of paris.