Search SchoolNGR

Wednesday, 20 May 2026
Register . Login

Chemistry Past Questions and Answers

Jamb 1979 Chemistry Questions

Question 36:
The solution of a sample in a tube will be identified as a chloride if it gives
  • A A white precipitate on addition of AgNO<sub style='font-size: smaller;'>3</sub> and barium chloride solutions
  • B A white precipiate when acidified with HCI, and then AgNO<sub style='font-size: smaller;'>3</sub> solution added
  • C A white precipitate when acidified with dilute HNO<sub style='font-size: smaller;'>3</sub> and then AgNO<sub style='font-size: smaller;'>3</sub> solution added
  • D A white precipitate when acidified with dilute H<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4</sub> and then barium nitrate solution added
  • E A pungent smell of chlorine gas when dilute HCI and MnO<sub style='font-size: smaller;'>2</sub> are added
View Answer & Explanation
Question 37:
Hydrogenation may be effected by
  • A The removal of hydrogen from an alkane in the presence of a catalyst
  • B The addition of hydrogen to an alkane in the presence of a catalyst
  • C The addition of hydrogen to an alkyne
  • D The removal of hydrogen from an alkyne
  • E The addition of hydrogen to an ethyl alcohol
View Answer & Explanation
Question 38:
Two metallic ions associated with hard water are
  • A Copper and zinc
  • B Magnesium and silver
  • C Calcium and magnesium
  • D Potassium and tin
  • E Sodium and lead
View Answer & Explanation
Question 39:
Bronze is an alloy of
  • A Copper, zinc and nickel
  • B Aluminium and copper
  • C Copper and zinc
  • D Tin and zinc
  • E Tin and copper
View Answer & Explanation
Question 40:
Phosphorus burns in oxygen according to the equation P4 + 502 → P4O10. How many litres of oxygen will be required at S.T.P for complete oxidation of 12.4g of phosphorus? [P = 31,O = 16 and molar volume of a gas at S.T.P = 22.4 litres]
  • A 5. 20
  • B 11. 20
  • C 2. 24
  • D 20. 20
  • E 6. 20
View Answer & Explanation