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GK Questions: General Science(Chemistry) – Set 21

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Hello Aspirants. Welcome to Online General Knowledge section in Affairs cloud, which is important for all the competitive exams. We have created Some questions related to General Science(Chemistry) !!!

  1. …………………………. is least compressible
    4.All of these
    5.None of these
    Answer – 1.Solid
    Explanation :
    Solid is least compressible, Because their atoms are tightly packed

  2. Brass is a ………………………..
    1.Heterogenus Compound
    2.Homogenous Mixture
    3.Heterogenus Mixture
    4.Homogenous Compound
    5.None of these
    Answer – 2.Homogenous Mixture
    Explanation :
    Brass is a homogeneous mixture (solid solution) of copper and zinc. Again each metal by itself is a pure substance. Only when they are mixed on an atomic level are they a homogeneous mixture (or solid solution).

  3. When steam is passed over hot coke, it produces which type of gas ?
    1.Mixed gas
    2.Tear gas
    3.Poisonous gas
    4.Synthesis gas
    5.None of these
    Answer – 4.Synthesis gas
    Explanation :
    Water gas is a synthesis gas, containing carbon monoxide and hydrogen. It is a useful product but requires careful handling due to its flammability and the risk of carbon monoxide poisoning.

  4. Which acid is also known as king of the acids ?
    1.Hydrochloric acids
    2.Citric Acids
    3.Sulphuric Acids
    4.Acetic acids
    5.None of these
    Answer – 3.Sulphuric Acids
    Explanation :
    Sulphuric acid is called the king of chemicals because it has a large number of applications. It finds applications in manufacturing either directly or indirectly.

  5. ………………….is responsible for green colour in fireworks
    5.None of these
    Answer – 2.Barium
    Explanation :
    Barium is a chemical element with symbol Ba and atomic number 56. Barium compounds are added to fireworks to impart a green color.

  6. Sea Weeds contain which of the following ?
    5.None of these
    Answer – 4.Iodine
    Explanation :
    Edible seaweeds accumulate iodine from seawater.

  7. Which phosphorus is kept in water?
    5.None of these
    Answer – 3.Yellow 
    Explanation :
    Phosphorus exists in four or more allotropic forms: white (or yellow), red, and black (or violet).
    White phosphorus should be kept under water, as it is dangerously reactive in air, and it should be handled with forceps, as contact with the skin may cause severe burns.

  8. ………….is a metal you can melt in the palm of your hand 
    5.None of these
    Answer – 3.Gallium
    Explanation :
    Gallium is a metal you can melt in the palm of your hand from solid into liquid form

  9. Annealing is done to …………………………..
    1.Reduce brittleness
    2.Improve  ductility
    3.Increase brittleness
    4.Both 1 and 2
    5.Both 1 and 3
    Answer – 4.Both 1 and 2
    Explanation :
    Annealing is a heat process whereby a metal is heated to a specific temperature /colour and then allowed to cool slowly. This softens the metal which means  to improve  ductility and reduce brittleness.

  10. Gold is alloyed with ………………… to make it harder
    5.None of these
    Answer – 1.Copper
    Explanation :
    The pure gold gold  is too soft on its own and is therefore hardened by the addition of alloying elements, copper, silver, nickel, palladium and zinc.