Chemistry MCQs

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Anthracite, often referred to as hard coal, is a hard, compact variety of coal that has a submetallic luster. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highest ranking of coals.

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Sodium Alkyl Sulphate and Benzene Sulphate are typical examples of Synthetic Detergents. Synthetic detergents are man-made cleansing agents that function similarly to soap. These compounds were developed during World War II when a shortage of natural oils led to a search of alternative substances. The advanced features of synthetic detergents include improved cleansing efficacy, resistance to water hardness, and the ability to function in acidic conditions.

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In an electrochemical cell, the half cell where oxidation takes place is known as oxidation half cell and the half cell where reduction takes place is known as reduction half cell. Oxidation takes place at anode which is negatively charged and reduction takes place at cathode which is positively charged.

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Cassiterite is a mineral that is primarily composed of tin dioxide (SnO2). It is the most important source of tin, and is also used as a semi-precious gemstone. Cassiterite is typically found in igneous and metamorphic rocks, and is often associated with other minerals such as quartz, feldspar, and mica. It has a high melting point and is resistant to weathering, making it a useful material for many industrial applications. The name “cassiterite” comes from the Greek word “kassiteros,” which means “tin.”

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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 quicklime (calcium oxide) is added to water, it reacts exothermically to form calcium hydroxide (slaked lime). This reaction produces heat and releases water vapor, which causes bubbling. The reaction can be represented as: [ ext{CaO} + ext{H}_2 ext{O}
ightarrow ext{Ca(OH)}_2 + ext{heat} ] Trivia: Quicklime is used in various applications, including steelmaking and water treatment, and was historically used in ancient construction.

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Gun metal is an alloy primarily composed of copper, tin, and zinc. Specifically, it typically contains about 88% copper, 10% tin, and 2% zinc. This alloy is known for its strength, corrosion resistance, and ability to withstand high temperatures, making it ideal for manufacturing firearms and artillery. The term “gun metal” dates back to the 15th century when it was used for cannons and other weaponry.

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L.P.G. (Liquefied Petroleum Gas) primarily consists of propane and butane. It is used as fuel for heating, cooking, and vehicles. Propane (C3H8) and butane (C4H10) are both byproducts of natural gas processing and petroleum refining. LPG is favored for its high energy content and clean-burning properties.

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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.

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Hydrogen peroxide is a compound of Hydrogen and Oxygen.