Mole and Molarity Calculations MCQs

  1. Number of moles in 44 g of CO₂:
    A) 0.5
    B) 1
    C) 2
    D) 4
    Answer: B
  2. Molar mass of CaCO₃:
    A) 90 g/mol
    B) 100 g/mol
    C) 110 g/mol
    D) 95 g/mol
    Answer: B
  3. Moles in 100 g CaCO₃:
    A) 0.5
    B) 1
    C) 2
    D) 0.25
    Answer: B
  4. 1 mole of H₂ contains:
    A) 1 atom
    B) 2 atoms
    C) 6.02 × 10²³ molecules
    D) 3 × 10²³ atoms
    Answer: C
  5. Number of atoms in 1 mole of O₂:
    A) 6.02 × 10²³
    B) 1.2 × 10²⁴
    C) 3 × 10²³
    D) 2 × 10²³
    Answer: B
  6. 0.5 M solution in 2 L contains moles:
    A) 0.5
    B) 1
    C) 2
    D) 4
    Answer: B
  7. Molarity formula can also be written as:
    A) M = mass/moles
    B) M = moles × volume
    C) M = moles/volume
    D) M = volume/mass
    Answer: C
  8. Moles in 2 L of 3 M solution:
    A) 3
    B) 5
    C) 6
    D) 1
    Answer: C
  9. Volume of 1 mole gas at STP:
    A) 24 L
    B) 22.4 L
    C) 20 L
    D) 25 L
    Answer: B
  10. Molar mass of KCl:
    A) 70.5 g/mol
    B) 74.5 g/mol
    C) 75.5 g/mol
    D) 72.5 g/mol
    Answer: B
  11. Moles in 74.5 g KCl:
    A) 0.5
    B) 1
    C) 2
    D) 3
    Answer: B
  12. Molarity after dilution:
    A) increases
    B) decreases
    C) constant
    D) doubles
    Answer: B
  13. Moles in 0.25 L of 4 M solution:
    A) 0.5
    B) 1
    C) 2
    D) 4
    Answer: B
  14. Molar mass of MgSO₄:
    A) 118 g/mol
    B) 120 g/mol
    C) 122 g/mol
    D) 124 g/mol
    Answer: B
  15. Moles in 60 g MgSO₄:
    A) 0.5
    B) 1
    C) 2
    D) 0.25
    Answer: A
  16. Number of molecules in 0.5 mole:
    A) 3.01 × 10²³
    B) 6.02 × 10²³
    C) 1 × 10²³
    D) 2 × 10²³
    Answer: A
  17. Molarity depends on:
    A) moles and volume
    B) mass only
    C) temperature only
    D) pressure only
    Answer: A
  18. Unit of molarity:
    A) mol/kg
    B) mol/L
    C) g/mol
    D) kg/L
    Answer: B
  19. Moles in 98 g H₂SO₄:
    A) 0.5
    B) 1
    C) 2
    D) 3
    Answer: B
  20. Volume of 2 moles gas at STP:
    A) 22.4 L
    B) 44.8 L
    C) 11.2 L
    D) 20 L
    Answer: B
  21. 1.5 M solution means:
    A) 1.5 g/L
    B) 1.5 mol/L
    C) 1.5 kg/L
    D) 1.5 L/mol
    Answer: B
  22. Moles in 0.1 L of 2 M solution:
    A) 0.1
    B) 0.2
    C) 2
    D) 1
    Answer: B
  23. Molar mass of Al₂O₃:
    A) 100 g/mol
    B) 102 g/mol
    C) 104 g/mol
    D) 98 g/mol
    Answer: B
  24. Moles in 204 g Al₂O₃:
    A) 1
    B) 2
    C) 3
    D) 4
    Answer: B
  25. Number of atoms in 2 moles of He:
    A) 6.02 × 10²³
    B) 1.2 × 10²⁴
    C) 2 × 10²³
    D) 3 × 10²³
    Answer: B
  26. Dilution keeps constant:
    A) volume
    B) moles
    C) molarity
    D) temperature
    Answer: B
  27. Moles = M × V
    A) True
    B) False
    C) Depends
    D) None
    Answer: A
  28. Molar mass of HCl:
    A) 35.5 g/mol
    B) 36.5 g/mol
    C) 37.5 g/mol
    D) 38.5 g/mol
    Answer: B
  29. Moles in 73 g HCl:
    A) 1
    B) 2
    C) 3
    D) 0.5
    Answer: B
  30. Volume required for 2 moles in 1 M:
    A) 1 L
    B) 2 L
    C) 3 L
    D) 0.5 L
    Answer: B
  31. Molarity of 1 mole in 500 mL:
    A) 1 M
    B) 2 M
    C) 0.5 M
    D) 4 M
    Answer: B
  32. Convert 500 mL to L:
    A) 0.5 L
    B) 5 L
    C) 50 L
    D) 0.05 L
    Answer: A
  33. Moles in 36.5 g HCl:
    A) 0.5
    B) 1
    C) 2
    D) 3
    Answer: B
  34. Molar mass of Ca(OH)₂:
    A) 72 g/mol
    B) 74 g/mol
    C) 76 g/mol
    D) 78 g/mol
    Answer: B
  35. Moles in 74 g Ca(OH)₂:
    A) 1
    B) 2
    C) 0.5
    D) 3
    Answer: A
  36. Molarity =
    A) mass × volume
    B) moles/volume
    C) volume/mass
    D) density × volume
    Answer: B
  37. Moles in 18 g H₂O:
    A) 1
    B) 2
    C) 3
    D) 0.5
    Answer: A
  38. Number of molecules in 3 moles:
    A) 6.02 × 10²³
    B) 1.8 × 10²⁴
    C) 3 × 10²³
    D) 2 × 10²⁴
    Answer: B
  39. Molarity decreases when:
    A) volume increases
    B) moles increase
    C) temperature decreases
    D) pressure increases
    Answer: A
  40. Molarity of 2 moles in 2 L:
    A) 2 M
    B) 1 M
    C) 0.5 M
    D) 4 M
    Answer: B
  41. Moles in 0.2 L of 5 M solution:
    A) 1
    B) 0.5
    C) 2
    D) 5
    Answer: A
  42. Molar mass of Na₂CO₃:
    A) 104 g/mol
    B) 106 g/mol
    C) 108 g/mol
    D) 110 g/mol
    Answer: B
  43. Moles in 106 g Na₂CO₃:
    A) 0.5
    B) 1
    C) 2
    D) 3
    Answer: B
  44. 0.01 M is:
    A) very concentrated
    B) dilute
    C) saturated
    D) neutral
    Answer: B
  45. Molarity unit can be written as:
    A) mol dm⁻³
    B) g dm⁻³
    C) kg mol⁻¹
    D) L mol⁻¹
    Answer: A
  46. Moles in 10 L of 0.1 M solution:
    A) 1
    B) 0.1
    C) 10
    D) 5
    Answer: A
  47. Molarity of 0.5 moles in 250 mL:
    A) 2 M
    B) 1 M
    C) 0.5 M
    D) 4 M
    Answer: A
  48. Number of atoms in 1 mole of Na:
    A) 6.02 × 10²³
    B) 3 × 10²³
    C) 2 × 10²³
    D) 1 × 10²³
    Answer: A
  49. Moles = mass / molar mass
    A) True
    B) False
    C) Depends
    D) None
    Answer: A
  50. Mole concept is used to measure:
    A) volume
    B) mass
    C) amount of substance
    D) density
    Answer: C

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