Chemistry GK Questions Quiz-17

Chemistry GK Questions Quiz-17

Chemistry Multiple Choice Questions (MCQs) Quiz for State and UPSC Civil Services Examinations. Objective Questions on Chemistry for competitive examinations.

    321. The drug ‘Marijuana’ is a

    (1) sedative
    (2) mental stimulant
    (3) hallucinating substance
    (4) tranquillizer
    Answer:
    321. (1) Cannabis, also known as marijuana is a preparation of the Cannabis plant intended for use as a
    psychoactive drug and as medicine. Cannabis indica is known for sedative effects and preferred night time as medical cannabis.

    322. The material known in commerce as Terylene is a

    (1) Synthetic fibre
    (2) Natural fibre
    (3) Modified natural fibre
    (4) Blend of cotton and silk
    Answer:
    322. (1) Terylene is the name for a synthetic polyester fibre. It is a synthetic polyester fibre or fabric based on terephthalic acid, characterized by lightness and crease resistance and used for clothing, sheets, ropes, sails, etc.

    323. Among the fuels given below, the one with highest calorific value is

    (1) Coke 
    (2) Coal
    (3) Wood 
    (4) Natural gas
    Answer:
    323. (4) The calorific values of different fuels (in Kcal/kg) in dry state are: Wood: 3500; Coal: 4000-7000; Coke: 6500; and Natural Gas: 8600 Kcal/kg.

    324. The chemical used in embalming biological materials is

    (1) formaldehyde in water
    (2) formaldehyde in methanol
    (3) ethylene glycol
    (4) gaseous formaldehyde
    Answer:
    324. (1) Embalming fluids use formaldehyde as a preservative. Formaldehyde is the simplest aldehyde
    with the chemical formula HCHO. Formalin is a solution of formaldehyde in water, usually with a small amount of methanol added. Modern formaldehyde based embalming fluids are much kinder to the
    environment than those used in previous years.

    325. Which of the following is a monoatomic gas?

    (1) Oxygen 
    (2) Neon
    (3) Nitrogen 
    (4) Fluorine
    Answer:
    325. (2) All elements will be monatomic in the gas phase at sufficiently high temperatures. At standard
    temperature and pressure (STP), all of the noble gases are monatomic. These are helium, neon, argon,
    krypton, xenon and radon. Monatomic hydrogen comprises about 75% of the elemental mass of the
    universe.

    326. Sodium bicarbonate is commercially known as

    (1) Washing soda
    (2) Baking soda
    (3) Caustic soda
    (4) Soda lime
    Answer:
    326. (2) Baking Soda is Sodium bicarbonate or sodium hydrogen carbonate. It is primarily used in cooking (baking), as a leavening agent. It reacts with acidic components in batters, releasing carbon dioxide, which causes expansion of the batter and forms the characteristic texture and grain in pancakes, cakes, quick breads, soda bread, and other baked and fried foods.

    327. Coal is formed from

    (1) crude oil
    (2) deposit of animal waste
    (3) coke
    (4) compressed and hardened biomass
    Answer:
    327. (4) A fossil fuel, coal forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, after that bituminous coal, and lastly anthracite. This involves biological and geological processes that take place over a long period.

    328. Commercial Vaseline is derived from

    (1) plant gums 
    (2) coal tar
    (3) wool wax 
    (4) petroleum
    Answer:
    328. (4) Vaseline is a brand of petroleum jelly based products owned by Anglo-Dutch company Unilever. While Vaseline can be used as a lubricant, it is also a useful moisture insulator for local skin conditions characterized by tissue dehydration. Vaseline helps protect minor cuts and burns.

    329. Colour imparted to the Bunsen flame by strontium salt is

    (1) bluish green
    (2) apple-green
    (3) brick red
    (4) crimson red
    Answer:
    329. (4) A flame test is performed by introducing a sample into the blue flame of a bunsen burner and noting any change in the colour of the flame. The tests can be used to detect the presence of some metallic elements in salts. With strontium salt, the colour of Bunsen flame ranges from crimson to red.

    330. A potato tuber has been cut into two halves. A few drops of iodine solution are placed on the cut surface of one of the halves. What colour change will be noticed?

    (1) From brown to blue-black
    (2) From brown to orange-red
    (3) From blue to pink
    (4) From pink to blue-green
    Answer:
    330. (1) The Iodine test is used to test for the presence of starch. Iodine solution — iodine dissolved in an aqueous solution of potassium iodide — reacts with the starch producing a purple black colour.

    331. Tear gas used by the police to disperse the mob contains

    (1) Carbon dioxide
    (2) Chlorine
    (3) Ammonia
    (4) Hydrogen sulphide
    Answer:
    331. (2) Tear gas, formally known as a lachrymatory agent, is a possibly lethal chemical weapon that stimulates the corneal nerves in the eyes to cause tears, pain, and even blindness. The compound 2-
    chlorobenzalmalononitrile (chemical formula: C10H5ClN2), is the defining component of a "tear gas"
    commonly referred to as CS gas, which is used as a riot control agent.

    332. Epsom salt is used

    (1) as purgative
    (2) in softening water
    (3) in paper industry
    (4) in making tooth paste
    Answer:
    332. (1) Magnesium sulfate is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen which is commonly called Epsom Salt. Because like other salts, it withdraws water from cells, Epsom salt is used as a fast-acting purgative in some types of poisoning, to draw water into the intestines, thus, reducing constipation; to withdraw toxins from the body; and to draw fluid from the brain in cases of cerebral edema.

    333. The common refrigerant in domestic refrigerator is

    (1) Neon 
    (2) Oxygen
    (3) Nitrogen 
    (4) Freon
    Answer:
    333. (4) Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander.

    334. The chemical name of “laughing gas’ is

    (1) Nitric oxide
    (2) Nitrogen dioxide
    (3) Nitrogen pentoxide
    (4) Nitrous oxide
    Answer:
    334. (4) Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.

    335. Brass is an alloy of

    (1) Lead and tin
    (2) Zinc and copper
    (3) Antimony, tin and lead
    (4) Zinc, tin and copper
    Answer:
    335. (2) Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties. By comparison, bronze is principally an alloy of copper and tin. Bronze does not necessarily contain tin, and a variety of alloys of copper, including alloys with arsenic, phosphorus, aluminium, manganese, and silicon, are commonly termed "bronze"

    336. The chemical name of rat poison is

    (1) zinc oxide
    (2) potassium cyanide
    (3) lead nitrate
    (4) zinc phosphide
    Answer:
    336. (4) Zinc phosphide is used as a rodenticide. A mixture of food and zinc phosphide is left where the rodents can eat it. The acid in the digestive system of the rodent reacts with the phosphide to generate the toxic phosphine gas.

    337. Which one of the following pairs is NOT correctly matched?

    (1) Haematite : Copper
    (2) Bauxite : Aluminium
    (3) Monazite : Thorium
    (4) Pitchblende : Uranium
    Answer:
    337. (1) Haematite is the mineral form of iron oxide (Fe2O3), one of several iron oxides. It is mined as the main ore of iron. Hematite is harder than pure iron, but much more brittle.

    338. Which of the following is used for refrigeration?

    (1) Sulphur dioxide
    (2) Chlorine
    (3) Freon
    (4) Phosphine
    Answer:
    338. (3) Common refrigerants used in domestic refrigerators are Freon, neon and nitrogen. It flows through four components of refrigerator again and again.

    339. Which of the following is used to denature ethanol ?

    (1) Methyl alcohol
    (2) Propyl alcohol
    (3) Phenol
    (4) Methane
    Answer:
    339. (1) Denatured alcohol is ethanol that has additives to make it undrinkable (poisonous), to discourage recreational consumption. Different additives are used to make it difficult to use distillation or other simple processes to reverse the denaturation. Methanol is commonly used both because its boiling point is close to that of ethanol and because it is toxic.

    340. The charcoal used to decolourise brown sugar solution is

    (1) Wood charcoal
    (2) Coconut charcoal
    (3) Animal charcoal
    (4) Sugar charcoal
    Answer:
    340. (3) A special characteristic of animal charcoal is its power to remove substances from solution. A brown solution of raw sugar is decolourized when boiled with animal charcoal. Other substances that are similarly removed from solution are indigo, litmus, iodine, the colouring-matter of red wine, the brown matter of peaty water or sewage, astringent principles, and certain basic salts, etc.


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