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Friday, 02 October 2026
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Chemistry Past Questions and Answers

Topic: Precipitation and action of acids on metals

Jamb Chemistry Questions - Precipitation and action of acids on metals

Question 1:
Hydrogen is not liberated when trioxonitrate(v)acid reacts with zinc because
  • A Zinx is not rendered passive by acid
  • B Hydrogen produced is oxidized to water
  • C Oxides of nitrogen are produced
  • D All nitrates are soluble in water
  • E Trioxonitrate(v)acid is a strong acid
View Answer & Explanation
Question 2:
How will a metal X, which reacts explosively with air and with dilute acids be best extracted from its ores?
  • A Electrolysis of solution of its salts
  • B Decomposition of its oxides
  • C Displacement from solution by an alkali metal
  • D Electroiysis of fused salt
View Answer & Explanation
Question 3:
Which of the following represents the balanced equation for the reaction of copper with concentrated trioxonitrate (V) acid?
  • A Cu <sub style='font-size: smaller;'>(s)</sub> + 2HNO <sub style='font-size: smaller;'>3(aq)</sub> → Cu (NO <sub style='font-size: smaller;'>3</sub>) <sub style='font-size: smaller;'>2(aq)</sub> + H <sub style='font-size: smaller;'>2(g)</sub>
  • B Cu <sub style='font-size: smaller;'>(s)</sub> + 4HNO <sub style='font-size: smaller;'>3(aq)</sub> → Cu (NO <sub style='font-size: smaller;'>3</sub>) <sub style='font-size: smaller;'>2(aq) </sub> + 2H <sub style='font-size: smaller;'>2</sub>O <sub style='font-size: smaller;'>(1)</sub> + 2NO <sub style='font-size: smaller;'>2(g)</sub>
  • C 3Cu <sub style='font-size: smaller;'>(s)</sub> + 8HNO<sub style='font-size: smaller;'>3(aq)</sub> → 3Cu (NO<sub style='font-size: smaller;'>3</sub>)<sub style='font-size: smaller;'>2(aq)</sub> + 4H<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>(1)</sub> + 2NO<sub style='font-size: smaller;'>(g)</sub>
  • D 3Cu<sub style='font-size: smaller;'>(s)</sub> + 4HNO<sub style='font-size: smaller;'>3(aq)</sub> → 3Cu(NO <sub style='font-size: smaller;'>3</sub>) <sub style='font-size: smaller;'>2(aq)</sub> + 2H <sub style='font-size: smaller;'>2</sub>O <sub style='font-size: smaller;'>(1)</sub> + 2NO <sub style='font-size: smaller;'>(g)</sub>
View Answer & Explanation
Question 4:
Which of the following metals will liberate hydrogen from steam or dilute acid?
  • A Copper
  • B Iron
  • C Lead
  • D Mercury
View Answer & Explanation
Question 5:
The number of hydrogen ions in 4.9 g of tetraoxosulphate (IV) acid is?
(S = 32, O =16, H = 1, Na = 6.02 x 1023
  • A 3.01 x 10<sub style='font-size: smaller;'>22</sub>
  • B 6.02 x 10<sub style='font-size: smaller;'>22</sub>
  • C 3.01 x 10<sub style='font-size: smaller;'>23</sub>
  • D 6.01 x 10<sub style='font-size: smaller;'>23</sub>
View Answer & Explanation