Level 1 — Basic Recall (1–10)

1. Define a mole.

2. What is Avogadro’s number?

3. State the formula for moles from mass and molar mass.

4. Define molar mass.

5. What is a balanced chemical equation?

6. Write the formula for calculating number of particles.

7. State the molar volume of a gas at RTP.

8. Convert 250 cm³ to dm³.

9. Define limiting reagent.

10. What is percentage yield?

Level 2 — Understanding (11–20)

11. Why must equations be balanced for stoichiometric calculations?

12. Explain the difference between empirical and molecular formulas.

13. Why is molar mass necessary for mole calculations?

14. Explain why theoretical yield is usually higher than actual yield.

15. What is the relationship between moles and volume for gases?

16. Why do we convert all volumes to dm³?

17. Explain the term “stoichiometric ratio.”

18. How does a limiting reagent control product formation?

19. Describe how to find moles from concentration.

20. Explain why % yield can never exceed 100%.

Level 3 — Application (21–30)

21. Calculate moles in 36 g of water.

22. Determine molar mass of Mg(NO₃)₂.

23. Find the mass of CO₂ produced when 10 g CaCO₃ decomposes.

24. Calculate moles of gas in 72 dm³ at RTP.

25. Determine concentration of a solution with 0.5 mol in 2 dm³.

26. Calculate the volume of 0.1 mol gas at RTP.

27. Find empirical formula from C=40%, H=6.7%, O=53.3%.

28. Determine limiting reagent given 10 g H₂ and 80 g O₂.

29. Calculate theoretical yield of NH₃ in the Haber process.

30. Determine number of molecules in 0.25 mol nitrogen.

Level 4 — Analysis (31–40)

31. Explain why side reactions lower yield.

32. Predict how doubling one reactant affects yield.

33. Analyse the effect of impure reactants in stoichiometry.

34. Compare molar volume changes at different temperatures.

35. Discuss when percentage purity calculations are needed.

36. Solve a multi-step problem involving gas, mass, and concentration.

37. Determine reactant purity from experimental yield.

38. Explain how to choose a suitable indicator in titration calculation.

39. Analyse titration results to determine concentration.

40. Calculate moles in a hydrated salt given water loss on heating.

Level 5 — Exam/Challenge (41–50)

41. Predict mass of product formed from mixed reagents with two limiting steps.

42. Determine molecular formula using mass spectrum data.

43. Calculate water of crystallization from heating curves.

44. Solve titration involving dilution factors.

45. Solve a combustion analysis problem to determine empirical formula.

46. Calculate partial pressures in a gas mixture.

47. Use stoichiometry to determine gas density.

48. Interpret percentage composition to find molecular formula.

49. Solve a full back-titration exam-style problem.

50. Explain how stoichiometry is used in industrial processes with numerical example.