Chemistry MCQs

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The noble gases are the chemical elements in group 18 of the periodic table. They are the most stable due to having the maximum number of valence electrons their outer shell can hold. This chemical series contains helium, neon, argon, krypton, xenon, and radon.

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MTBE is a gasoline additive, used as an oxygenate to raise the octane number. Its use is controversial in the US and declining in that country in part because of its occurrence in groundwater and legislation favoring ethanol.

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Tartaric acid occurs naturally in many fruits such as grapes, bananas, tamarinds, and citrus. Its salt, potassium bitartrate, commonly known as cream of tartar, develops naturally in the process of winemaking. It is commonly mixed with sodium bicarbonate and is sold as baking powder used as a leavening agent in food preparation. The acid itself is added to foods as an antioxidant E334 and to impart its distinctive sour taste.

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Noble gases are characterized by their low reactivity. The reason for this is their full electron shell, which makes them very stable and unlikely to engage in chemical reactions. The six noble gases that occur naturally are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn). Despite the inertness of noble gases, some of them like Xenon are known to form compounds.

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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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The three most stable isotopes of hydrogen: Protium, Deuterium and Tritium. Para hydrogen is not an isotope of hydrogen. Molecules of hydrogen in which the spins of both the nuclei are in the opposite direction are called Para hydrogen.

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A the s-orbital can accommodate only two electrons, two groups (1 & 2) belong to the s-block of the Periodic Table.

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Sodium carbonate is generally prepared by Solvay Process.

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The compounds of carbon having double or triple bonds between the carbon atoms are known as unsaturated carbon compounds.

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In electrolytic refining, the impure metal is made to act as anode. A strip of the same metal in pure form is used as cathode. Copper is generally refined using an electrolytic method.