Chemistry GK Questions Quiz-19

Chemistry GK Questions Quiz-19

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

    361. ‘Vinegar’ is a commercial name of

    (1) Oxalic acid
    (2) Hydrochloric acid
    (3) Acetic acid
    (4) Citric acid
    Answer:
    361. (3) Vinegar is a liquid substance consisting mainly of acetic acid (CH3CO2H) and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. It is today mainly used in the kitchen as a general cooking ingredient.

    362. Which metal does not undergo corrosion due to the formation of oxide layer?

    (1) Copper 
    (2) Iron
    (3) Aluminium 
    (4) Zinc
    Answer:
    362. (3) Corrosion is an oxidation reaction with atmospheric oxygen in the presence of water on the surface of a metal. Iron corrodes more quickly than most other transition metals to form an iron oxide. Aluminium also undergoes an oxidation reaction, but does not oxidize and corrode as quickly as its reactivity suggests. Once a thin oxide layer of Al2O3 has formed on the surface, it forms a barrier to oxygen and water to prevent further corrosion of the aluminium.

    363. Submarines move under water. They have engines that run on

    (1) Petrol and oxygen
    (2) Diesel 
    (3) Batteries
    (4) Steam
    Answer:
    363. (2) Early submarines used a direct mechanical connection between the engine and propeller,
    switching between diesel engines for surface running, and electric motors for submerged propulsion. Diesel electric submarines have a stealth advantage over their nuclear counterparts.

    364. The Bhopal gas tragedy was caused by the gas

    (1) Methyl chloride
    (2) Methyl Iso Cyanide
    (3) Methyl Iso Cyanate
    (4) Methyl Cyanide
    Answer:
    364. (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. The toxic substance made its way in and around the
    shantytowns located near the plant.

    365. In upper layer of atmosphere ozone is formed by

    (1) the action of ultraviolet rays on oxygen
    (2) the combination of oxygen molecules
    (3) subjecting oxygen to high pressure
    (4) the action of nitrogen on oxygen in atmosphere
    Answer:
    365. (1) The majority of tropospheric ozone formation occurs when nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs), such as xylene, react in the atmosphere in the presence of sunlight containing ultra violet rays. NOx, CO, and VOCs are called ozone precursors. CO + 2O2 + CO2+O3

    366. Molasses a by-product in the manufacture of sugar, is converted into

    (1) alcohol 
    (2) paper
    (3) fuel 
    (4) pulp
    Answer:
    366. (1) Molasses are the principal ingredient in the distillation of rum. Rum is therefore common in
    regions of the world where sugarcane or sugar beets are heavily cultivated. It is used in the manufacture
    of ethyl alcohol for industry and as an ingredient in cattle feed.

    367. Silver nitrate solution is kept in brown bottles in laboratory because

    (1) it reacts with ordinary white bottles
    (2) brown bottles stops the passage of light through it
    (3) brown bottles do not react with it
    (4) brown bottles react with it
    Answer:
    367. (2) Silver Nitrate is stored in dark bottles in a laboratory to prevent chemical reactions as it is sensitive to light. It reacts to light to produce silver metal.

    368. Which of these acids is not organic in origin?

    (1) Lactic acid 
    (2) Sulphuric acid
    (3) Citric acid 
    (4) Oxalic acid
    Answer:
    368. (2) Sulfuric acid is produced from sulfur, oxygen and water via the conventional contact process (DCDA) or the wet sulfuric acid process (WSA). Sulfuric acid can be produced in the laboratory by burning sulfur in air and dissolving the gas produced in a hydrogen peroxide solution. SO2 + H2O2 ® H2SO4

    369. Lead pencil contains

    (1) lead
    (2) ferrous sulphide
    (3) lead sulphide
    (4) graphite
    Answer:
    369. (4) Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.

    370. Solder is an alloy of

    (1) lead, zinc 
    (2) copper, lead
    (3) tin, lead 
    (4) sodium, lead
    Answer:
    370. (3) Tin/lead solders, also called soft solders, are commercially available with tin concentrations
    between 5% and 70% by weight. The greater the tin concentration, the greater the solder’s tensile and
    shear strengths. Alloys commonly used for electrical soldering are 60/40 Tin/lead (Sn/Pb) which melts at 370 °F or 188 °C and 63/37 Sn/Pb used principally in electrical/electronic work.

    371. Name two elements that find wide application in transistor industry

    (1) Silicon and Germanium
    (2) Carbon and Platinum
    (3) Iridium and Germanium
    (4) Tungsten and Platinum
    Answer:
    371. (1) A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. Semiconductor material (date first used): the metalloids germanium (1947) and silicon (1954) — in amorphous, polycrystalline and mono-crystalline form; the compounds gallium arsenide (1966) and silicon carbide (1997), the alloy silicon-germanium (1989), the allotrope of carbon graphene (research ongoing since 2004), etc.

    372. The energy of the sun is mainly due to

    (1) nuclear fission
    (2) radioactivity
    (3) heat
    (4) nuclear fusion
    Answer:
    372. (4) The Sun is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen
    nuclei into helium. Nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to photons which are released through a cycle that even our sun uses.

    373. Gelatin is mostly used in making ice–creams in order to

    (1) prevent making a colloid
    (2) stabilise the colloid and prevent crystallisation
    (3) stabilise mixture
    (4) enrich the aroma
    Answer:
    373. (2) Gelatine, being a colloid, has the property of preventing crystallization. In ice lollies and ice-cream this is demonstrated by the formation of a very fine crystal structure on freezing. This goes much further in that gelatine stabilized ice-cream does not become grainy or sandy due to the slow crystallisation of lactose with time.

    374. Which of the following is used to remove ink and rust stains on cloth?

    (1) Oxalic acid 
    (2) Alcohol
    (3) Ether 
    (4) Kerosene oil
    Answer:
    374. (1) Oxalic acid is a reducing agent and its conjugate base, known as oxalate (C2O2–2), is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.

    375. Two elements which can form a large number of compounds are

    (1) Carbon and Hydrogen
    (2) Carbon and Nitrogen
    (3) Carbon and Oxygen
    (4) Carbon and Sulphur
    Answer:
    375. (1) The carbon-hydrogen bond (C-H bond) is a bond between carbon and hydrogen atoms that can be found in many organic compounds. Compound classes consisting solely of C-H bonds and C-C bonds are alkanes, alkenes, alkynes, and aromatic hydrocarbons. Collectively they are known as
    hydrocarbons.

    376. An inert gas mixed with oxygen given to patients suffering from restricted breathing is

    (1) Helium 
    (2) Krypton
    (3) Radon 
    (4) Argon
    Answer:
    376. (1) Heliox is a breathing gas composed of a mixture of helium (He) and oxygen (O2). Heliox has been used medically since the 1930s, and although the medical community adopted it initially to alleviate symptoms of upper airway obstruction, its range of medical uses has since expanded greatly, mostly because of the low density of the gas.

    377. An example of major air pollutant is

    (1) Oxygen
    (2) Carbon monoxide
    (3) Helium
    (4) Carbon dioxide
    Answer:
    377. (2) Carbon monoxide (CO) is a colourless, odorless, non-irritating but very poisonous gas which is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.

    378. The Fungus which is used in the alcohol industry is

    (1) Mushroom
    (2) Candida Aibicans
    (3) Yeast
    (4) Rhizopus
    Answer:
    378. (3) Yeasts are eukaryotic microorganisms classified in the kingdom Fungi. By fermentation, the yeast species Saccharomyces cerevisiae converts carbohydrates to carbon dioxide and alcohols – for
    thousands of years the carbon dioxide has been used in baking and the alcohol in alcoholic beverages.

    379. Gold dissolves in

    (1) Hydrochloric acid
    (2) Nitric acid
    (3) Aqua-regia
    (4) Acetic acid
    Answer:
    379. (3) Aqua regia or nitro-hydrochloric acid is a highly corrosive mixture of acids, a fuming yellow or red solution. It was named so because it can dissolve the so-called royal or noble metals, gold and platinum.

    380. Which halide is used in making sensitive emulsion on photograhic film?

    (1) Sodium chloride
    (2) Silver bromide
    (3) Silver iodide
    (4) Silver chloride
    Answer:
    380. (2) Silver bromide, a soft, pale-yellow, water insoluble salt well known for its unusual sensitivity to light. This property has allowed silver halides to become the basis of modern photographic materials.


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