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Thursday, 21 May 2026
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Chemistry Past Questions and Answers

Jamb 1990 Chemistry Questions

Question 16:
Coal fire should not be used in poorly ventilated rooms because ?
  • A Of the accumulation of CO<sub style='font-size: smaller;'>2</sub> which causes dep sleep
  • B It is usually too hot
  • C Of the acumulation of CO which causes suffocation
  • D It removes most most of the gases in the rooms
View Answer & Explanation
Question 17:
The major component of the slag from the production of iron is?
  • A An alloy of calcium and iron
  • B Coke
  • C Impure iron
  • D Calcium trioxosilicate (IV)
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Question 18:
Sodium hydrogen should be stored in properly closed containers because it?
  • A Readily asborbs water vapour to air
  • B Is easily oxidize by atmospheric oxygen
  • C Turns golden yellow when exposed to light
  • D Melts at a low temperature
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Question 19:
To make coloured glasses, small quantities of oxides of metals which form coloured silicates are often added to the reaction mixture consisting of Na2CO3 and SiO2. Such a metals is a?.
  • A Pottasium
  • B Barium
  • C Zinc
  • D Copper
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Question 20:
Which of the following compounds gives a yellow residue when heated and also reacts with aqueous sodium hydroxide to give a white gelatinous precipitate soluble in excess sodium hydroxide solution?
  • A (NH<sub style='font-size: smaller;'>4</sub>)CO<sub style='font-size: smaller;'>3</sub>
  • B ZnCO<sub style='font-size: smaller;'>3</sub>
  • C Al<sub style='font-size: smaller;'>2</sub>(SO<sub style='font-size: smaller;'>4</sub>)<sub style='font-size: smaller;'>3</sub>
  • D PbCO[sub][/sub]3
View Answer & Explanation