1. The atomic, formula or molecular mass of a substance expressed in grams is called one
Answer: A. mole
Chemistry Class 10 Unit 3: Stoichiometry MCQs
44 multiple choice questions with the correct answer for each. Tap an option to check yourself, or switch on "Show all answers".
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2. The SI unit used to express the amount of a substance is the
Answer: B. mole
3. One mole of water (H₂O) has a mass of
Answer: C. 18 g
4. One mole of oxygen molecules (O₂) has a mass of
Answer: D. 32 g
5. One mole of NaCl has a mass of
Answer: A. 58.5 g
6. In 2H₂ + O₂ → 2H₂O, 2 moles of hydrogen react with ______ mole(s) of oxygen.
Answer: D. 1
7. In 2CH₃OH + 3O₂ → 2CO₂ + 4H₂O, the moles of oxygen used to burn 3.50 moles of methanol are
Answer: C. 5.25
8. In 2CH₃OH + 3O₂ → 2CO₂ + 4H₂O, burning 3.50 moles of methanol produces ______ moles of water.
Answer: B. 7.00
9. In N₂ + 3H₂ → 2NH₃, the moles of hydrogen required to make 8.0 moles of NH₃ are
Answer: A. 12
10. What mass of CO₂ is produced by the combustion of each mole of CH₄?
Answer: B. 44 g
11. The mass of aluminium in 204 g of Al₂O₃ is (Al = 27, O = 16)
Answer: C. 108 g
12. One mole of any gas at RTP occupies a volume of
Answer: D. 24 dm³
13. The volume of 2.5 moles of chlorine gas at RTP is
Answer: C. 60 dm³
14. The number of moles of oxygen in 50.0 dm³ of oxygen gas at RTP is about
Answer: B. 2.08
15. The volume occupied by 0.80 mole of N₂ at RTP is
Answer: A. 19.2 dm³
16. A flask contains 500 cm³ of SO₂ at RTP. The mass of SO₂ is about (S = 32, O = 16)
Answer: D. 1.33 g
17. The percentage of magnesium in MgO (Mg = 24, O = 16) is
Answer: D. 60
18. Which compound has the highest percentage by mass of nitrogen?
Answer: C. N₂H₄
19. A limiting reactant is the reactant that
Answer: B. is completely consumed in a reaction
20. The reactant which is consumed earlier and gives the least quantity of product is the
Answer: A. limiting reactant
21. 10 moles of H₂ and 7 moles of O₂ react to form water. The limiting reactant is
Answer: D. H₂
22. 200 g of Zn reacts with 200 g of H₂SO₄ (Zn = 63.5, H₂SO₄ = 98). The limiting reactant is
Answer: C. H₂SO₄
23. The mass of hydrogen produced when 2.04 mol of H₂SO₄ reacts completely with zinc is
Answer: B. 4.08 g
24. In C₂H₄ + 3O₂ → 2CO₂ + 2H₂O, 0.480 mol C₂H₄ reacts with 1.08 mol O₂. The limiting reactant is
Answer: A. O₂
25. 68.1 g of CaCO₃ (100 g/mol) is mixed with 51.6 g of HCl (36.5 g/mol) in CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O. The limiting reactant is
Answer: B. CaCO₃
26. The amount of product actually obtained in a reaction is called the
Answer: D. actual yield
27. The percentage yield is calculated as
Answer: C. (actual yield / theoretical yield) × 100
28. The actual yield of CuSO₄ is 1.85 g and the theoretical yield is 2.5 g. The percentage yield is
Answer: A. 74 %
29. The theoretical yield of Cu is 0.5072 g and the actual yield is 0.392 g. The percentage yield is about
Answer: C. 77.3 %
30. A compound has 40 % C, 6.7 % H and 53.3 % O. Its empirical formula is
Answer: D. CH₂O
31. A compound with empirical formula CH₂O and molar mass 180 g/mol has the molecular formula
Answer: B. C₆H₁₂O₆
32. A sample weighs 6.3 g and contains 4.2 g of pure compound. The percentage purity is
Answer: A. 66.67 %
33. An impure sample of CaCO₃ weighs 70 g and 56 g is pure. The percentage purity is
Answer: C. 80 %
34. Molarity is the number of moles of solute per
Answer: B. dm³ of solution
35. 40 g of urea (60 g/mol) dissolved to make 500 cm³ of solution has a molarity of about
Answer: D. 1.334 M
36. 0.05 mol of KMnO₄ in 600 cm³ of solution has a molarity of about
Answer: A. 0.083 M
37. A solution contains 20 g of salt in 2 dm³ of solution. Its strength is
Answer: B. 10 g/dm³
38. 10.0 g of NaCl in 500 cm³ of solution has a strength of
Answer: D. 20 g/dm³
39. The mass of NaCl (58.5 g/mol) needed to prepare 250 cm³ of 0.5 M NaCl is about
Answer: A. 7.3 g
40. The dilution formula is
Answer: C. M₁V₁ = M₂V₂
41. The volume of 4 M KNO₃ needed to prepare 500 cm³ of 1 M KNO₃ is
Answer: C. 125 cm³
42. In the titration of HCl with NaOH using phenolphthalein, the end point is when the
Answer: B. pink colour just disappears
43. In a titration, 25.0 cm³ of 0.10 M NaOH neutralised 20.0 cm³ of HCl. The molarity of HCl is
Answer: A. 0.125 M
44. 1.00 g of impure Na₂CO₃ needs 25.0 cm³ of 0.1 M HCl (Na₂CO₃ + 2HCl → 2NaCl + CO₂ + H₂O). The percentage purity is about
Answer: D. 13.25 %
About Chemistry Class 10 Unit 3 MCQs (Federal Board)
These 44 Chemistry MCQs cover Class 10 Unit 3: Stoichiometry of the Federal Board (FBISE) SSC-II (Class 10) syllabus. They are SLO-based MCQs as per the new pattern for FBISE exams. Each question has four options and the correct answer is shown, so you can practise for the annual examination and find the topics you still need to revise. You can also read the Stoichiometry notes for this chapter. Download the Stoichiometry MCQs as a PDF using the button at the top of this page.