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Saturday, 13 June 2026
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Chemistry Past Questions and Answers

Jamb 1981 Chemistry Questions

Question 16:
The brown coloration in nitric acid prepared in the laboratory can be removed by?
  • A Heating the acid
  • B Bubbling air through the acid
  • C Cooling the acid
  • D Adding a decolorizing agent
  • E Adding a base
View Answer & Explanation
Question 17:
Which of the following processes takes place during electrolysis?
  • A Positive ions are discharged at the anode bby gaining sufficient electrons to become neutral
  • B Negative ions are dicharged at the anode by gaining suficient electrons to become neutral
  • C Positive ions are discharged at the anode by losing sufficient electrons to become neutral
  • D Negative ions are discharge at the anode by losing sufficient electrons to become neutral
  • E Nothing happens
View Answer & Explanation
Question 18:
In the preparation of ammonia, which of the following is used as the drying agent?
  • A CaO
  • B CaCI<sub style='font-size: smaller;'>2</sub>
  • C Conc. H<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4</sub>
  • D P<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>5</sub>
  • E H<sub style='font-size: smaller;'>3</sub>PO<sub style='font-size: smaller;'>4</sub>
View Answer & Explanation
Question 19:
Which of the following can have an isomer?
  • A C<sub style='font-size: smaller;'>2</sub>H<sub style='font-size: smaller;'>4</sub>
  • B C<sub style='font-size: smaller;'>4</sub>H<sub style='font-size: smaller;'>10</sub>
  • C C<sub style='font-size: smaller;'>3</sub>H<sub style='font-size: smaller;'>8</sub>
  • D C<sub style='font-size: smaller;'>2</sub>H<sub style='font-size: smaller;'>6</sub>
  • E C<sub style='font-size: smaller;'>6</sub>H<sub style='font-size: smaller;'>6</sub>
View Answer & Explanation
Question 20:
Allotropes are elements having?
  • A Different physical but the same chemical properties
  • B Different chemical but the same physical properties
  • C The same chemical and physical properties
  • D Different atomic structure
  • E The same position in the periodic table
View Answer & Explanation