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Sunday, 05 April 2026
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Chemistry Past Questions and Answers

Jamb Chemistry Questions

Question 6:
Fe\(_2\)O\(_{3(s)}\) + 2Al\(_{(s)}\) → Al\(_2\)O\(_3\) + 2Fe\(_{(s)}\). If the heats of formation of Al\(_2\)O\(_3\) and Fe\(_2\)O\(_3\) are - 1670 kJmol\(^{-1}\) and - 822 kJmol\(^{-1}\) respectively, the enthalpy change in kJ for the reaction is ?
  • A +2492
  • B +848
  • C -848
  • D -2492
View Answer & Explanation
Question 7:
Iron galvanized with zinc is cathodically protected from corrosion. This is because?
  • A Zinc has a more positive oxidation potential than iron
  • B Zinc has less positive oxidation potential than iron
  • C Bith have the same oxidation potential
  • D Zinc is harder than iron
View Answer & Explanation
Question 8:
Which of the following samples will react fastest with dilute trioxonitrate (V) acid?
  • A 5 g of lumps of CacO3 at 25°C
  • B 5 g of powered CacO3 at 25°
  • C 5 g of lumps of CaCO3 at 50°C
  • D 5 g of powered CaCO3 AT 50°C
View Answer & Explanation
Question 9:
In the reaction:
2Hl(g) ↔ H2(g) + l2(g)' ΔH = 10 kj;
The concentration of iodine in the equilibrium mixture can be increased by?
  • A Raising the pressure
  • B Raising the temperature
  • C Adding a catalyst
  • D Lowering the pressure
View Answer & Explanation
Question 10:
Which of the following gases can be collected by the upward displacement of air?
  • A NO
  • B H 2
  • C NH3
  • D Cl 2
View Answer & Explanation