Chemistry MCQs

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Polyvinyl chloride (PVC) is made from the monomer vinyl chloride (CH2 =CHCl). It is used for making raincoats, handbags, toys including dolls, electrical goods and as a covering of electrical wires.

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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.

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Galvanisation is a method of protecting steel and iron from rusting by coating them with a thin layer of zinc

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Kazimierz Funk (1884 – 1967) was a Polish biochemist, and one of the first to formulate the concept of Vitamins.

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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.

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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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chemical oxygen demand is a measure of water quality and is amount of organic pollutants found in surface water. Potassium permanganate has been used for many years to measure COD

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The correct answer is Octaoxygen. Octaoxygen (O8) is an allotrope of oxygen that can exist in multiple phases under varying pressures and temperatures. It was first synthesized in 2001 and is notable for its unique molecular structure, which consists of eight oxygen atoms. Ozone (O3) is well-known but does not exhibit multiple phases like octaoxygen. Tetraoxygen (O4) is less stable and not commonly referenced in the same context.

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The Mizoroki-Heck reaction is a cross-coupling reaction that typically involves the coupling of aryl halides with alkenes. It is primarily catalyzed by palladium (Pd) complexes. Palladium is favored due to its ability to facilitate the oxidative addition and reductive elimination steps essential for the reaction. Rhodium, while also a transition metal, is less commonly used for this specific reaction. The Mizoroki-Heck reaction is important in organic synthesis for forming carbon-carbon bonds and is widely utilized in pharmaceuticals and materials science.

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An aqueous solution of sodium acetate is basic in nature. This is because sodium acetate is a salt derived from a strong base (sodium hydroxide) and a weak acid (acetic acid). When dissolved in water, it undergoes hydrolysis to form sodium ions and acetate ions. The acetate ions react with water to form acetic acid and hydroxide ions, thus creating a basic solution.