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Tuesday, 03 November 2026
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Chemistry Past Questions and Answers

Jamb 1978 Chemistry Questions

Question 6:
Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore,
  • A P will form an electrovalent bond with R
  • B Q will form a covalent bond with S
  • C R will form an electrovalent bond with S
  • D Q will form an electrovalent bond with S
  • E Q will form a covalent bond with R
View Answer & Explanation
Question 7:
An element X forms the following compounds with chlorine; XCl4, XCl3, XCl2. This illustrates the
  • A Law of multiple proportions
  • B Law of chemical proportions
  • C Law of simple proportions
  • D Law of conservation of mass
  • E Law of definite proportions
View Answer & Explanation
Question 8:
The oxidation state of chlorine in potassium chlorate is
  • A +1
  • B +2
  • C +3
  • D +5
  • E +7
View Answer & Explanation
Question 9:
When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are;
  • A Nitrogen and carbondioxide
  • B The rare gases
  • C Nitrogen and oxygen
  • D Nitrogen and the rare gases
  • E Nitrogen, carbondioxide and the rare gases
View Answer & Explanation
Question 10:
When heat is absorbed during a chemical reaction, the reaction is said to be
  • A Thermodynamic
  • B Exothermic
  • C Isothermal
  • D Endothermic
  • E Thermostatic
View Answer & Explanation