Chemistry MCQs

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Methanol (CH₃OH) is also known as Wood Alcohol. It’s a solvent in many chemical processes and is a component of automobile antifreeze.

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Zeolite is hydrated Sodium Alumino-silicate capable of exchanging reversible Sodium ions for hardness producing ions in water. It is also use as softening of water. It is used to remove the permanent hardness in water due to Calcium or Magnesium sulphates.

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Hydrogen (H2) gas is utilized in the manufacture of Vanaspati ghee from vegetable oils. The process involves hydrogenation, a chemical reaction between molecular hydrogen (H2) and another compound or element. Hydrogenation of vegetable oils helps to convert them into a semisolid form that resembles ghee, often used as a cheaper alternative to butter or ghee in cooking.

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Technetium was the first artificially produced element. It was isolated by Carlo Perrier and Emilio Segrè in 1937. Technetium was created by bombarding molybdenum atoms with deuterons that had been accelerated by a device called a cyclotron.

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Aluminum is considered a “Green Metal” primarily due to its high recycling rate. Approximately 75% of all aluminum ever produced is still in use today, as it can be recycled indefinitely without losing quality. This process saves energy—recycling aluminum uses about 95% less energy than producing new aluminum from bauxite ore. Additionally, recycling reduces greenhouse gas emissions and conserves natural resources, making aluminum a sustainable choice in various applications.

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Isobutane, which is known in the industry as R600A has been used in several domestic refrigerators in recent times because it is an excellent refrigerant and non-ozone depleting substance with low global warming potential. The only drawback is that it is highly inflammable.

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The correct composition of biogas released through anaerobic bio-digester system is:
Methane (CH4) – 50–75 %
Carbon dioxide (CO2) – 25–50%
Nitrogen (N2) – 0–10%
Hydrogen (H2) – 0–1%
Hydrogen sulphide (H2S) – 0–3%

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Silver halides and most commonly silver Chloride is used in Photochromic lens. But for plastic photochromic lenses, some organic products such as oxazines and naphthopyrans are used.

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An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer. The emission of a gamma ray from an excited nuclear state allows the nucleus to lose energy and reach either a lower energy state, sometimes its ground state. In certain cases, the excited nuclear state following a nuclear reaction or other type of radioactive decay, has a half live that is more than 100 to 1000 times longer than the average 10-12 seconds, and this excited state is referred to as a metastable nuclear excited state. Some nuclei are able to stay in this metastable excited state for minutes, hours, days, or occasionally far longer, before undergoing gamma decay, in which they undergo radioactive decay with primary emission of a gamma ray.

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Sodium carbonate is generally prepared by Solvay Process.