Chemistry MCQs

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Bitumen is a mixture of organic liquids that are highly viscous, black, sticky, soluble in carbon disulfide and composed of highly condensed polycyclic aromatic hydrocarbons.

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Bananas contain potassium-40, a radioactive isotope of potassium, which makes them slightly radioactive. The radiation is very minor and not dangerous at all to humans, but it is enough to trigger sensitive radiation sensors. The potassium provides bananas some of their nutritional benefits as well.

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Pewter is primarily composed of tin, typically around 85-95%, with the remainder often consisting of copper, antimony, or bismuth. Historically, pewter was used for making utensils and decorative items due to its malleability and low melting point. The use of tin in pewter dates back to ancient civilizations, including the Romans and Egyptians, who valued it for its corrosion resistance and ease of casting.

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When Mendeleev published his periodic table in 1869, noble gases had not yet been discovered. The first noble gas, argon, was identified in 1894 by Lord Rayleigh and William Ramsay. In contrast, lanthanides and actinides were recognized later, but their existence was inferred from Mendeleev’s predictions. Halogens, including elements like chlorine and iodine, were known prior to Mendeleev’s work.

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Flint is a sedimentary rock. It’s a type of microcrystalline quartz in the chert family. Flint is known for its sharp edges and ability to be easily flaked into various shapes. It was widely used by early humans to make a variety of tools, including:  Knives, Scrapers, Points, Axe-heads, Hammers, Choppers. Flint is often found along streams and beaches. It’s close behind diamond in hardness and fractures easily to give razor sharp edges.

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The mixture of CO and H₂ produced is known as water gas or synthesis gas.

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Plaster of Paris is the common name of calcium sulphate hemihydrate because half molecule of water is attached with calcium sulphate. The chemical formula of plaster of Paris is CaSO₄.1/2H₂O.

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Sodium carbonate is commonly known as Washing soda. Sodium Hydrogencarbonate is commonly known as Caustic soda. Ethanoic acid is commonly known as Acetic acid. calcium oxychloride is commonly known Bleaching powder.

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Stainless steel is also known as inox steel. It is an alloy of Iron, chromium and nickel. It is corrosion resistant and molybdenum is added to increase corrosion resistance in reducing acids.

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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.