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Tuesday, 03 November 2026
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Chemistry Past Questions and Answers

Jamb 1979 Chemistry Questions

Question 11:
Helium atoms are chemically unreactive because
  • A There are no electrons around the nucleus
  • B The number of protons equals the number of electrons
  • C There are equal number of protons and neutrons in the nucleus
  • D The outer electron shell is completely filled
  • E The atoms contain only protons
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Question 12:
\(50cm^{3}\) of hydrogen are sparked with \(20cm^{3}\) of oxygen at \(100°C\) and \(1atm\) . The total volume of the residual gases in
  • A 50 cm<sup style='font-size: smaller;'>3</sup>
  • B 10 cm<sup style='font-size: smaller;'>3</sup>
  • C 40 cm<sup style='font-size: smaller;'>3</sup>
  • D 30 cm<sup style='font-size: smaller;'>3</sup>
  • E 70 cm<sup style='font-size: smaller;'>3</sup>
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Question 13:
How many grams of HBr would exactly be required to react with 2 g of propyne? (C =12, H=1, Br = 80)
  • A 4. 1 g
  • B 6. 1 g
  • C 8. 1g
  • D 16.2g
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Question 14:
When ammonium, potassium and calcium carbonates are each separately heated
  • A None of them will decompose
  • B Each of them will decompose to give carbondioxide and the respective oxide
  • C Ammonium carbonate and potassium carbonate will not decompose
  • D Only ammonium carbonate and the respective oxide
  • E Ammonium carbonate will decompose to give carbondioxide, water and ammonia
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Question 15:
If chlorine gas is bubbled into water and then this yellowish-green coloured solution is exposed to bright sunlight for a while
  • A The solution will give out chlorine gas and hydrogen chloried gas
  • B The solution will produce chlorine gas and oxygen
  • C The solution will give out solution will producing hypochloric acid
  • D The solution is decomposed giving out oxygen, hydrogen and chlorine
  • E The solution will give out oxygen gas leaving behind aqueous hydrochloric acid
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