Search SchoolNGR

Friday, 14 August 2026
Register . Login

Chemistry Past Questions and Answers

Topic: Separation processes

Jamb Chemistry Questions - Separation processes

Question 1:
A gas jar was inverted over burning yellow phosphorus floating over water in a beaker. After burning, the water level was found to rise in the gas jar. The water level rises because
  • A Pressure inside the gas jar is greater than pressure outside it
  • B The air in the gas jar had been used up by burning
  • C Oxygen in the gas jar had been used up by burning
  • D Nitrogen in the gas jar had been used up by burning
  • E The temperature in the jar had risen considerably
View Answer & Explanation
Question 2:
A gas jar was inverted over burning yellow phosphorus floating over water in a beaker. After burning, the water level was found to rise in the gas jar. The water level rises because
  • A Pressure inside the gas jar is greater than pressure outside it
  • B The air in the gas jar had been used up by burning
  • C Oxygen in the gas jar had been used up by burning
  • D Nitrogen in the gas jar had been used up by burning
  • E The temperature in the jar had risen considerably
View Answer & Explanation
Question 3:
Consider the solubility curves of three salts X, Y and Z given in the diagram. If each solution of the salt contains 200 g, and is heated to 100oC, which solution or solutions will deposit 100 g of the solute when suddenly cooled to 0oC?
  • A X only
  • B Y only
  • C Z only
  • D X and Z
  • E Y and Z
View Answer & Explanation
Question 4:
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 5:
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