Search SchoolNGR

Saturday, 15 August 2026
Register . Login

Chemistry Past Questions and Answers

Topic: Evaporation

Jamb Chemistry Questions - Evaporation

Question 1:
A solution X on mixing with AgNO3 solution, gives a white precipitate solution in NH3. A Solution Y, when added to X, also gives a white precipiate which is soluble on boiling. Solution Y contains?
  • A Ag<sup style='font-size: smaller;'>+</sup>ion
  • B Pb<sup style='font-size: smaller;'>2+</sup>ion
  • C Pb<sup style='font-size: smaller;'>4+</sup>ion
  • D Zn<sup style='font-size: smaller;'>2+</sup>ion
  • E Al<sup style='font-size: smaller;'>3+</sup>ion
View Answer & Explanation
Question 2:
Copper sulphate solution was electrolysed using the apparatus show above. Which of the following changes are observed?
  • A The bulb lights and copper is deposited at both electrodes
  • B The bulb lights and copper is deposited at the anode and disappears from the cathode
  • C The bulb lights and copper is deposited at the cathode and oxygen liberated at the anode
  • D The bulb lights and copper is deposited at the cathode and disappears from the anode
  • E The bulb lights but no additional changes are observed
View Answer & Explanation
Question 3:
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 4:
A gas that turns a filter paper previously soaked in lead ethanoate solution black is?
  • A Hyrogen chloride
  • B Hydrogen sulphide
  • C Sulphur (IV) oxide
  • D Sulphur (VI) oxide
View Answer & Explanation
Question 5:
The leachate of a certain plant ash is used in local soap making because it contains
  • A Sodium chloride and potassium hydroxide
  • B Sodium hydroxide
  • C Potassium hydroxide
  • D Soluble carbonates and hydrogen carbonates
View Answer & Explanation