Chemistry GK Questions Quiz-24

Chemistry GK Questions Quiz-24

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

    461. The chief source for the production of nitrogeneous fertilizers is :

    (1) Ammonia
    (2) Nitric acid
    (3) Nitrogen
    (4) Nitrogen dioxide
    Answer:
    461. (1) Nitrogen fertilizers are often made using the HaberBosch process which uses natural gas (CH4+) for the hydrogen and nitrogen gas from the air at an elevated temperature and pressure in the presence of a catalyst to form ammonia as the end product. This ammonia is used as a feedstock for other nitrogen fertilizers, such as anhydrous ammonium nitrate and urea.

    462. The element used for making solar cells is

    (1) Magnesium 
    (2) Sodium
    (3) Calcium 
    (4) Silicon
    Answer:
    462. (4) Materials presently used for photovoltaic solar cells include mono-crystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium selenide/sulfide.

    463. Which of the following is an iron ore ?

    (1) Bauxite 
    (2) Magnetite
    (3) Lignite 
    (4) Nitrite
    Answer:
    463. (2) Magnetite is a mineral, one of the two common naturally occurring oxides of Iron. It is the most magnetic of all the naturally occurring minerals on Earth.

    464. Which one of the following is an example of a gel ?

    (1) Cheese
    (2) Milk
    (3) Face cream
    (4) Shaving cream
    Answer:
    464. (3) A gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels consist of a solid three-dimensional network that spans the volume of a liquid medium
    and ensnares it through surface tension effects. Shaving creams in a can are commonly dispensed as
    a foam or a gel.

    465. Bakelite is a copolymer of Phenol and

    (1) Formaldehyde
    (2) Acetaldehyde
    (3) Benzaldehyde
    (4) Cinnaldehyde
    Answer:
    465. (1) Bakelite is an early plastic. It is a thermosetting phenol formaldehyde resin, formed from an elimination reaction of phenol with formaldehyde.

    466. When a spoon is to be electroplated with nickel the spoon is

    (1) dipped in a nickel sulphate solution
    (2) made anode and a pure nickel rod, the cathode
    (3) made cathode and a pure nickel red, the anode
    (4) coated with nickel sulphate and dried
    Answer:
    466. (3) Electroplating is the deposition by electrolysis of a coating of metal upon a conducting surface. The simplest system makes the object to be plated the negative electrode (cathode) or plate in a galvanic couple. Thus a spoon or other object may be connected by a wire to a plate of nickel. The process that occurs on the spoon is called reduction and, therefore, the spoon is also referred to as a cathode.

    467. The Bhopal tragedy was caused by the gas

    (1) phosgene
    (2) carbon monoxide
    (3) methyl isocyanate
    (4) chlorine
    Answer:
    467. (3) The Bhopal disaster occurred on the night of 2–3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate gas and other chemicals.

    468. Which one of the following contributes largely to the ‘green house effect’ ?

    (1) Ozone
    (2) Carbon monoxide
    (3) Carbon dioxide
    (4) Water vapour
    Answer:
    468. (4) The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide,
    methane, nitrous oxide, and ozone. When these gases are ranked by their direct contribution to the
    greenhouse effect in percentage terms, the most important are: Water vapour: 36-72 per cent; Carbon
    dioxide: 9-26 per cent; Methane: 4-9 per cent; and Ozone:3-7 per cent.

    469. The gas used to dilute oxygen for breathing by deep sea divers is:

    (1) Neon 
    (2) Argon
    (3) Nitrogen 
    (4) Helium
    Answer:
    469. (4) Helium is used since it has very low (almost nonexistent) narcotic properties. The nitrogen in air is highly narcotic at depth and adding helium allows one to dive without the effects of narcosis (where one's mind is impaired).

    470. Bleaching powder is prepared by passing :

    (1) Chlorine over slaked lime
    (2) Oxygen over slaked lime
    (3) Carbon dioxide over slaked lime
    (4) Chlorine over quick lirne
    Answer:
    470. (1) Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 +
    2Ca(OH)2 (slaked lime) ® Ca (OCl)2 + CaCl2 + 2H20. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.

    471. Gas released during Bhopal tragedy was :

    (1) Sodium isothiocyanate
    (2) Potassium isothiocyanate
    (3) Ethyl isothiocyanate
    (4) Methyl isothiocyanate
    Answer:
    471. (4) Methyl isocyanate is an intermediate chemical in the production of carbamate pesticides. As a highly toxic and irritating material, it is extremely hazardous to human health. It was the principal toxin involved in the Bhopal disaster, which killed nearly 8,000 people initially and approximately 20,000 to 30,000 people in total.

    472. Which of the following statements are correct about chloroform?

    a. Liquid fuel
    b. Anaesthetic in nature
    c. Produces phosgene
    d. Fire extinguisher
    (1) a, b 
    (2) a, c
    (3) b, c 
    (4) d, a
    Answer:
    472. (3) Chloroform was once a widely used anesthetic. Its vapor depresses the central nervous system of a patient, allowing a doctor to perform various otherwise painful procedures. Chronic chloroform exposure can damage the liver where chloroform is metabolized to phosgene.

    473. Which of the following is not a method of preparing oxygen?

    (1) Electrolysis of water
    (2) Fractional distillation of liquid air
    (3) Decomposition of potassium permanganate
    (4) Decomposition of manganese dioxide
    Answer:
    473. (4) One of the two chemical methods starts from natural manganese dioxide and converts it using
    dinitrogen tetroxide and water to manganese nitrate solution. Evaporation of the water leaves the crystalline nitrate salt. At temperatures of 400°C, the salt decomposes, releasing N2O4 and leaving a residue of purified manganese dioxide.

    474. Which one of the following is not a characteristic feature of alloys? They are

    (1) Compounds
    (2) Mixtures
    (3) Solutions
    (4) Homogeneous systems
    Answer:
    474. (4) An alloy is a mixture or metallic solid solution composed of two or more elements. So they are
    heterogeneous systems. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal (heat treatment) history. Alloys usually have different properties from those of the component elements.

    475. Permanent – hardness of water may be removed by addition of

    (1) Alum
    (2) Sodium carbonate
    (3) Lime
    (4) Potassium Permangante
    Answer:
    475. (2) Sodium carbonate (also known as washing soda or soda ash) is a sodium salt of carbonic acid. In domestic use, it is used as a water softener in laundering. It competes with the magnesium and calcium ions in hard water and prevents them from bonding with the detergent being used. Sodium carbonate can be used to remove grease, oil and wine stains.

    476. Of the following, which one pollutes the air of a big city ?

    (1) Copper 
    (2) Chromium
    (3) Lead 
    (4) Cadmium
    Answer:
    476. (3) The most common source of lead air pollution is from metal processing, but there are other
    manufacturing and industry sources as well. The highest lead air pollution levels are found near battery
    manufacturing and iron and other metal producing plants. Lead air pollution is a dangerous form of
    pollution because of the way lead builds up in our bodies.

    477. Wood spirit is

    (1) Methyl alcohol
    (2) Ethyl alcohol
    (3) Butyl alcohol
    (4) Propyl alcohol
    Answer:
    477. (1) Methanol is also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits. It acquired the name "wood alcohol" because it was once produced chiefly as a byproduct of the destructive distillation of wood. Modern methanol is produced in a catalytic industrial process directly from carbon monoxide, carbon dioxide, and hydrogen.

    478. Which of the following processes is used for the production of Biodiesel ?

    (1) Transamination
    (2) Transcription
    (3) Transesterification
    (4) Translation
    Answer:
    478. (3) Biodiesel production is the process of producing the biofuel, biodiesel, through the chemical reactions trans-esterification and esterification. This involves vegetable or animal fats and oils being reacted with short-chain alcohols (typically methanol or ethanol).

    479. One property of ammonia is

    (1) It is insoluble in water
    (2) It is a odourless gas
    (3) It is a yellowish gas
    (4) Its aqueous solution turns red litmus blue
    Answer:
    479. (4) The main use of litmus is to test whether a solution is acidic or basic. For instance, ammonia gas, which is alkaline, colours the red litmus paper blue.

    480. Find the odd one:

    (1) Marble 
    (2) Chalk
    (3) Limestone 
    (4) Slaked lime
    Answer:
    480. (4) Calcium carbonate, or CaCO3, is found in natural forms as chalk, limestone, and marble, produced by the sedimentation of the shells of small fossilized snails, shellfish, and coral over millions of years. Calcium hydroxide, traditionally called slaked lime, is an inorganic compound which is obtained when calcium oxide is mixed, or "slaked" with water.


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