GK-Chemistry Question and Answer

GK-Chemistry Question and Answer
41. The following are the half lives of four active isotopes. Which one of the following is the most
dangerous to handle?
  • 3 billion years
  • 100 years
  • 0.01 minute
  • 13 days
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42. The gas used for artificial ripening of green fruit is
  • ethylene
  • ethane
  • carbon dioxide
  • acetylene
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43. Zone refining is used for the purification of
  • Au
  • Ge
  • Ag
  • Cu
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44. The main chemical constituent of the oil of cardamom which is responsible for flavour of this oil is
  • cineole
  • engenol
  • geraniol
  • limonene
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45. The molecule which has the highest percentage of ionic character among the following is
A.
  • HI
  • HF
  • HCI
  • HBr
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46. The high reactivity of fluorine is due to
  • its high electro negativity
  • small size of fluorine atom
  • availability of d-orbitals
  • strong F - F bond
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47. The ionisation energy of hydrogen atom in the ground state is x KJ. The energy required for an
electron to jump from 2nd orbit to 3rd orbit is
  • 5x/36
  • 5x
  • 7.2 x
  • x/6
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48. The major constituent of air is
  • nitrogen
  • carbon dioxide
  • oxygen
  • hydrogen
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49.  The main chemical constituent of clay is
  • silicon oxide
  • aluminium borosilicate
  • zeolites
  • aluminium silicate
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50. The mineral containing both magnesium and calcium is
  • magnesite
  • calcite
  • carnallite
  • dolomite
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