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Tuesday, 03 November 2026
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Chemistry Past Questions and Answers

Jamb 1979 Chemistry Questions

Question 16:
12 g of solid protassium chlorate (KCIO) were added to 40 g of water and heated to dissolve all the solid. As the solution cools, crystals of potassium chlorate at 66 oC. The solubility of potassium chlorate at 66 oC is therefore
  • A 66
  • B 33
  • C 10
  • D 20
  • E 30
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Question 17:
In the electrolysis of dilute sulphuric acid using platinum electrodes, the products obtained at the anode and cathode are:
Anode Cathode
  • A Sulphur hydrogen
  • B Hydrogen oxygen
  • C Oxygen Hydrogen
  • D Hydrogen sulphate ions
  • E Sulphur oxygen
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Question 18:
The empirical formula of an oxide of nitrogen containing 30.4 per cent of nitrogen is (N=14.0,O=16.0)
  • A N<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>2</sub>
  • B NO
  • C NO<sub style='font-size: smaller;'>2</sub>
  • D N<sub style='font-size: smaller;'>2</sub>O
  • E N<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>3</sub>
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Question 19:
When a piece of charcoal enclosed in a cylinder containing air is ignited
  • A The toatl volume of air is increased
  • B The relative amount of oxygen present is increased
  • C The relative amount of nitrogen present is decreased
  • D The relative amount of carbondioxide present is increased
  • E The ratio of oxygen to nitrogen in the system is increased
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Question 20:
Indicate which of the following statements is not true as we move from left to right along the periodic Table:
  • A Atomic number of elements increases
  • B Atomic mass of elements increases
  • C Electropositive character of elements increases
  • D Electronegative character of elements increases
  • E Number of electrons in the outermost orbits of element increases
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