“Mole Concept” MCQ with Answer Explanation : NEET 2025.

Here below some basic MCQ’s of “Mole Concept” with answer which is explained in details. Let’s check one by one which is given in below.

1. What does one mole of a substance contain?
   a) 6.022 × 10²³ molecules
   b) 1 gram
   c) 22.4 liters at STP
   d) All of the above

Answer: a) 6.022 × 10²³ molecules

Explanation: One mole, known as Avogadro’s number, corresponds to 6.022 × 10²³ entities, whether they are atoms, molecules, or ions.

2. Which of the following statements about the mole is true?
   a) The mass of one mole of any element is its atomic mass in grams.
   b) Moles are only applicable to gases.
   c) One mole of a gas occupies 10 liters at STP.
   d) Moles are a measure of volume.

Answer: a) The mass of one mole of any element is its atomic mass in grams.

Explanation: The atomic mass of an element (in grams) gives the mass of one mole of that element, which is fundamental to stoichiometry.

3. At standard temperature and pressure (STP), one mole of any ideal gas occupies:
   a) 22.4 L
   b) 24 L
   c) 1 L
   d) 1 m³

Answer: a) 22.4 L

Explanation: Under STP conditions, one mole of an ideal gas occupies 22.4 liters, a key concept in gas laws.

4. How many grams are in 0.5 moles of NaCl (Molar mass = 58.5 g/mol)?
   a) 29.25 g
   b) 58.5 g
   c) 117 g
   d) 14.625 g

Answer: a) 29.25 g

Explanation: To find the mass, multiply the number of moles by the molar mass: 0.5 moles × 58.5 g/mol = 29.25 g.

5. Which of the following represents the mole ratio in the reaction: 2H₂ + O₂ → 2H₂O?
   a) 1:2:2
   b) 2:1:2
   c) 2:2:1
   d) 1:1:1

Answer: b) 2:1:2

Explanation: The coefficients in the balanced equation represent the mole ratios of the reactants and products.

6. Which of the following is the correct definition of a mole?
   a) The mass of an object
   b) The amount of substance containing the same number of entities as there are atoms in 12 g of carbon-12
   c) A unit of pressure
   d) A measure of temperature

Answer: b) The amount of substance containing the same number of entities as there are atoms in 12 g of carbon-12

Explanation: A mole is defined based on Avogadro’s number, linking it to a specific quantity of carbon-12.

7. What is the molar mass of water (H₂O)?
   a) 18 g/mol
   b) 16 g/mol
   c) 20 g/mol
   d) 10 g/mol

Answer: a) 18 g/mol

Explanation: The molar mass of water is calculated by adding the masses of two hydrogen atoms (1 g/mol each) and one oxygen atom (16 g/mol).

8. How many moles are in 100 grams of Na (Molar mass = 23 g/mol)?
   a) 2.17 moles
   b) 4.35 moles
   c) 1.5 moles
   d) 3.5 moles

Answer: a) 4.35 moles

Explanation: To find the number of moles, divide the mass by the molar mass: 100 g ÷ 23 g/mol ≈ 4.35 moles.

9. In the reaction: 4Fe + 3O₂ → 2Fe₂O₃, what is the mole ratio of iron to oxygen?
   a) 1:1
   b) 2:3
   c) 4:3
   d) 3:4

Answer: c) 4:3

Explanation: The coefficients in the balanced equation show that 4 moles of iron react with 3 moles of oxygen.

10. Which of the following represents a conversion factor for moles to grams?
    a) Molar mass
    b) Avogadro’s number
    c) Density
    d) Temperature

Answer: a) Molar mass

Explanation: Molar mass is used to convert between the number of moles and the mass of a substance.

11. How many molecules are in 2 moles of CO₂?
    a) 1.2 × 10²⁴
    b) 6.022 × 10²³
    c) 1.2044 × 10²⁴
    d) 12.044 × 10²³

Answer: a) 1.2 × 10²⁴

Explanation: Multiply the number of moles by Avogadro’s number: 2 moles × 6.022 × 10²³ molecules/mole.

12. If 1 mole of a substance has a mass of 10 g, what is its molar mass?
    a) 5 g/mol
    b) 10 g/mol
    c) 20 g/mol
    d) 15 g/mol

Answer: b) 10 g/mol

Explanation: The molar mass is the mass of one mole of the substance, which is given as 10 g.

13. What is the total number of moles in 50 g of KCl (Molar mass = 74.5 g/mol)?
    a) 0.67 moles
    b) 1.02 moles
    c) 0.75 moles
    d) 1.50 moles

Answer: a) 0.67 moles

Explanation: 50 g ÷ 74.5 g/mol ≈ 0.67 moles.

14. Which of the following is not a state function?
    a) Temperature
    b) Pressure
    c) Heat
    d) Volume

Answer: c) Heat

Explanation: Heat is not a state function; it depends on the path taken, unlike temperature, pressure, and volume.

15. What is the number of moles in 44 g of CO₂ (Molar mass = 44 g/mol)?
    a) 1 mole
    b) 2 moles
    c) 0.5 moles
    d) 3 moles

Answer: a) 1 mole

Explanation: 44 g ÷ 44 g/mol = 1 mole.

16. The mole ratio from the balanced equation 2Na + Cl₂ → 2NaCl is:
    a) 1:2
    b) 2:1
    c) 2:2
    d) 2:1:2

Answer: b) 2:1

Explanation: The mole ratio shows that 2 moles of sodium react with 1 mole of chlorine gas.

17. Which of the following compounds has the highest molar mass?
    a) H₂O
    b) CO₂
    c) NH₃
    d) C₆H₁₂O₆

Answer: d) C₆H₁₂O₆

Explanation: C₆H₁₂O₆ (glucose) has the highest molar mass compared to the others listed.

18. How many grams are in 3 moles of CaCl₂ (Molar mass = 110.98 g/mol)?
    a) 332.94 g
    b) 110.98 g
    c) 221.96 g
    d) 150 g

Answer: a) 332.94 g

Explanation: 3 moles × 110.98 g/mol = 332.94 g.

19. In a chemical reaction, if you have 2 moles of A and 3 moles of B, what is the mole ratio of A to B?
    a) 2:3
    b) 3:2
    c) 1:1.5
    d) 1.5:1

Answer: a) 2:3

Explanation: The ratio of the moles of A to B is directly taken from their coefficients.

20. If 5 moles of gas occupy a volume of 112 L at STP, what is the volume occupied by 1 mole?
    a) 22.4 L
    b) 56 L
    c) 28 L
    d) 44 L

Answer: a) 22.4 L

Explanation: At STP, 1 mole of an ideal gas occupies 22.4 L.

21. How many moles are in 12 g of C (Molar mass = 12 g/mol)?
    a) 1 mole
    b) 2 moles
    c) 0.5 moles
    d) 3 moles

Answer: a) 1 mole

Explanation: 12 g ÷ 12 g/mol = 1 mole.

22. Which of the following describes a chemical change?
    a) Dissolving salt in water
    b) Melting ice
    c) Rusting of iron
    d) Boiling water

Answer: c) Rusting of iron

Explanation: Rusting involves a chemical transformation, while the others are physical changes.

23. In the reaction 3H₂ + N₂ → 2NH₃, what is the mole ratio of H₂ to NH₃?
    a) 1:2
    b) 2:3
    c) 3:2
    d) 1:1

Answer: c) 3:2

Explanation: The coefficients indicate that 3 moles of hydrogen produce 2 moles of ammonia.

24. What is the molar mass of sodium sulfate (Na₂SO₄)?
    a) 122 g/mol
    b) 142 g/mol
    c) 138 g/mol
    d) 98 g/mol

Answer: b) 142 g/mol

Explanation: Molar mass is calculated as (2 × 23) + 32 + (4 × 16) = 142 g/mol.

25. If you have 4.5 moles of a substance, how many molecules do you have?
    a) 2.71 × 10²³
    b) 2.71 × 10²⁴
    c) 4.5 × 6.022 × 10²³
    d) 3.01 × 10²⁴

Answer: b) 2.71 × 10²⁴

Explanation: 4.5 moles × 6.022 × 10²³ molecules/mole = 2.71 × 10²⁴ molecules.

26. What is the number of grams in 2.5 moles of C₆H₁₂O₆ (Molar mass = 180 g/mol)?
    a) 450 g
    b) 360 g
    c) 270 g
    d) 540 g

Answer: a) 450 g

Explanation: 2.5 moles × 180 g/mol = 450 g.

27. Which of the following gases will have the largest volume at STP when 1 mole is considered?
    a) N₂
    b) O₂
    c) CO₂
    d) All will have the same volume

Answer: d) All will have the same volume

Explanation: At STP, 1 mole of any ideal gas occupies the same volume (22.4 L).

28. How many moles are in 88 g of CH₄ (Molar mass = 16 g/mol)?
    a) 2 moles
    b) 5.5 moles
    c) 6 moles
    d) 4 moles

Answer: a) 5.5 moles

Explanation: 88 g ÷ 16 g/mol = 5.5 moles.

29. In the reaction: 2H₂ + O₂ → 2H₂O, how many moles of H₂ are needed to produce 3 moles of H₂O?
    a) 2.5 moles
    b) 3 moles
    c) 4.5 moles
    d) 3.5 moles

Answer: a) 2.5 moles

Explanation: The mole ratio shows that for every 2 moles of H₂O produced, 2 moles of H₂ are needed, so 3 moles of H₂O require 2.5 moles of H₂.

30. What is the molar mass of ammonium sulfate ((NH₄)₂SO₄)?
    a) 132 g/mol
    b) 132.14 g/mol
    c) 145 g/mol
    d) 150 g/mol

Answer: a) 132 g/mol

Explanation: Molar mass is calculated as (2 × 14) + (8 × 1) + 32 + (4 × 16) = 132 g/mol.

31. Which of the following indicates an increase in the number of moles?
    a) Combining two reactants to form one product
    b) Decomposing one reactant into multiple products
    c) Diluting a solution
    d) Evaporating a liquid

Answer: b) Decomposing one reactant into multiple products

Explanation: Decomposition typically increases the number of moles since one substance breaks into several.

32. In a mixture of gases, if the total pressure is 1 atm and the partial pressure of gas A is 0.3 atm, what is the mole fraction of gas A?
    a) 0.3
    b) 0.7
    c) 0.5
    d) 1.0

Answer: a) 0.3

Explanation: The mole fraction is the partial pressure divided by the total pressure: 0.3 atm ÷ 1 atm = 0.3.

33. How many grams are in 0.75 moles of NaOH (Molar mass = 40 g/mol)?
    a) 30 g
    b) 40 g
    c) 60 g
    d) 20 g

Answer: c) 30 g

Explanation: 0.75 moles × 40 g/mol = 30 g.

34. In a balanced equation, the coefficients represent:
    a) Mass ratios
    b) Mole ratios
    c) Volume ratios
    d) Energy ratios

Answer: b) Mole ratios

Explanation: The coefficients in a balanced equation indicate the relative number of moles of each substance involved in the reaction.

35. If the molar mass of a gas is 28 g/mol, how many grams are in 3 moles?
    a) 28 g
    b) 56 g
    c) 84 g
    d) 92 g

Answer: c) 84 g

Explanation: 3 moles × 28 g/mol = 84 g.

36. In the reaction: 2C₃H₈ + 7O₂ → 6CO₂ + 8H₂O, what is the mole ratio of propane to water?
    a) 1:4
    b) 2:8
    c) 1:3
    d) 2:4

Answer: b) 2:8

Explanation: The balanced equation shows that 2 moles of propane produce 8 moles of water, which simplifies to 1:4.

37. The mass of 0.25 moles of KNO₃ (Molar mass = 101 g/mol) is:
    a) 25.25 g
    b) 20.25 g
    c) 25 g
    d) 30.25 g

Answer: a) 25.25 g

Explanation: 0.25 moles × 101 g/mol = 25.25 g.

38. In a chemical equation, if the coefficients are doubled, what happens to the number of moles of each reactant and product?
    a) Doubled
    b) Halved
    c) Remains the same
    d) Tripled

Answer: a) Doubled

Explanation: Doubling the coefficients in a balanced equation doubles the moles of each substance.

39. How many molecules are in 0.5 moles of H₂O?
    a) 6.022 × 10²³
    b) 3.011 × 10²³
    c) 1.2044 × 10²³
    d) 1.5 × 10²²

Answer: b) 3.011 × 10²³

Explanation: 0.5 moles × 6.022 × 10²³ molecules/mole = 3.011 × 10²³ molecules.

40. What is the mass of 2 moles of MgO (Molar mass = 40 g/mol)?
    a) 80 g
    b) 60 g
    c) 20 g
    d) 40 g

Answer: a) 80 g

Explanation: 2 moles × 40 g/mol = 80 g.

41. The number of moles in 32 g of O₂ is:
    a) 1 mole
    b) 2 moles
    c) 0.5 moles
    d) 4 moles

Answer: a) 1 mole

Explanation: 32 g ÷ 32 g/mol = 1 mole.

42. If the molar mass of an unknown gas is 44 g/mol, how many moles are in 88 g?
    a) 2 moles
    b) 1 mole
    c) 4 moles
    d) 3 moles

Answer: a) 2 moles

Explanation: 88 g ÷ 44 g/mol = 2 moles.

43. How many moles are present in 5 g of NaCl (Molar mass = 58.5 g/mol)?
    a) 0.085 moles
    b) 0.1 moles
    c) 0.25 moles
    d) 0.3 moles

Answer: a) 0.085 moles

Explanation: 5 g ÷ 58.5 g/mol ≈ 0.085 moles.

44. In the equation 2Al + 3Cl₂ → 2AlCl₃, what is the mole ratio of aluminum to aluminum chloride?
    a) 1:2
    b) 2:3
    c) 2:2
    d) 3:2

Answer: a) 1:2

Explanation: The coefficients indicate that 2 moles of aluminum produce 2 moles of aluminum chloride.

45. Which of the following is a physical change?
    a) Combustion of gasoline
    b) Dissolving sugar in water
    c) Rusting of iron
    d) Baking bread

Answer: b) Dissolving sugar in water

Explanation: Dissolving sugar is a physical change since the substance remains chemically the same.

46. The term “mole” was first introduced by:
    a) Avogadro
    b) Dalton
    c) Gay-Lussac
    d) Boyle

Answer: a) Avogadro

Explanation: Avogadro introduced the concept of the mole in relation to the number of particles in a gas.

47. In a mixture of gases, if the mole fraction of gas A is 0.25, what is the partial pressure of gas A if the total pressure is 2 atm?
    a) 0.5 atm
    b) 1 atm
    c) 0.25 atm
    d) 0.75 atm

Answer: a) 0.5 atm

Explanation: Partial pressure = mole fraction × total pressure = 0.25 × 2 atm = 0.5 atm.

48. How many grams are in 1.5 moles of Na₂SO₄ (Molar mass = 142 g/mol)?
    a) 213 g
    b) 106 g
    c) 75 g
    d) 100 g

Answer: a) 213 g

Explanation: 1.5 moles × 142 g/mol = 213 g.

49. Which gas occupies a volume of 22.4 L at STP for 1 mole?
    a) O₂
    b) N₂
    c) CO₂
    d) All of the above

Answer: d) All of the above

Explanation: At STP, any ideal gas occupies 22.4 L for 1 mole.

50. In the reaction: 2H₂ + O₂ → 2H₂O, how many moles of O₂ are needed to react with 4 moles of H₂?
    a) 1 mole
    b) 2 moles
    c) 3 moles
    d) 4 moles

Answer: b) 2 moles

Explanation: The mole ratio shows that 2 moles of H₂ react with 1 mole of O₂; hence, 4 moles of H₂ need 2 moles of O₂.

51. How many grams are in 0.2 moles of KCl (Molar mass = 74.5 g/mol)?
    a) 14.9 g
    b) 15 g
    c) 20 g
    d) 25 g

Answer: a) 14.9 g

Explanation: 0.2 moles × 74.5 g/mol = 14.9 g.

52. The number of moles in 64 g of O₂ is:
    a) 1 mole
    b) 2 moles
    c) 3 moles
    d) 4 moles

Answer: b) 2 moles

Explanation: 64 g ÷ 32 g/mol = 2 moles.

53. In the reaction 4Fe + 3O₂ → 2Fe₂O₃, how many moles of Fe are required to react with 1 mole of O₂?
    a) 4/3 moles
    b) 2 moles
    c) 1.5 moles
    d) 3 moles

Answer: a) 4/3 moles

Explanation: The mole ratio indicates that 4 moles of Fe react with 3 moles of O₂, so 1 mole of O₂ requires 4/3 moles of Fe.

54. What is the molar mass of ammonium nitrate (NH₄NO₃)?
    a) 80 g/mol
    b) 90 g/mol
    c) 100 g/mol
    d) 150 g/mol

Answer: b) 90 g/mol

Explanation: Molar mass is calculated as (14 + 4) + (14 + 3 × 16) = 90 g/mol.

55. How many molecules are in 4 moles of glucose (C₆H₁₂O₆)?
    a) 2.41 × 10²³
    b) 2.41 × 10²⁴
    c) 1.81 × 10²⁴
    d) 3.01 × 10²²

Answer: b) 2.41 × 10²⁴

Explanation: 4 moles × 6.022 × 10²³ molecules/mole = 2.41 × 10²⁴ molecules.

56. The molar mass of phosphoric acid (H₃PO₄) is:
    a) 95 g/mol
    b) 98 g/mol
    c) 100 g/mol
    d) 105 g/mol

Answer: b) 98 g/mol

Explanation: Molar mass is calculated as (3 × 1) + (31) + (4 × 16) = 98 g/mol.

57. In a chemical reaction, if you have 1 mole of A and it reacts with 3 moles of B, what is the total number of moles of products formed if 1 mole of A is completely consumed?
    a) 1 mole
    b) 2 moles
    c) 4 moles
    d) 3 moles

Answer: c) 4 moles

Explanation: If 1 mole of A and 3 moles of B react, the total moles of products will be the sum of moles of A and B consumed.

58. What is the volume occupied by 3 moles of an ideal gas at STP?
    a) 33.6 L
    b) 67.2 L
    c) 22.4 L
    d) 60 L

Answer: b) 67.2 L

Explanation: 3 moles × 22.4 L/mole = 67.2 L.

59. The mass of 2.5 moles of CaCO₃ (Molar mass = 100 g/mol) is:
    a) 250 g
    b) 200 g
    c) 150 g
    d) 125 g

Answer: a) 250 g

Explanation: 2.5 moles × 100 g/mol = 250 g.

60. How many moles of K are in 100 g of KCl (Molar mass = 74.5 g/mol)?
    a) 1.35 moles
    b) 2.35 moles
    c) 1.5 moles
    d) 0.5 moles

Answer: a) 1.35 moles

Explanation: 100 g ÷ 74.5 g/mol = 1.35 moles of KCl, which contains 1.35 moles of K.

61. What is the number of grams in 0.1 moles of H₂SO₄ (Molar mass = 98 g/mol)?
    a) 9.8 g
    b) 10 g
    c) 20 g
    d) 15 g

Answer: a) 9.8 g

Explanation: 0.1 moles × 98 g/mol = 9.8 g.

62. In the reaction 2C₂H₄ + 5O₂ → 4CO₂ + 4H₂O, what is the mole ratio of ethylene to carbon dioxide?
    a) 1:2
    b) 1:4
    c) 2:4
    d) 5:4

Answer: b) 1:2

Explanation: The mole ratio is 2 moles of ethylene producing 4 moles of carbon dioxide, simplifying to 1:2.

63. How many moles are in 180 g of H₂O (Molar mass = 18 g/mol)?
    a) 6 moles
    b) 10 moles
    c) 5 moles
    d) 8 moles

Answer: a) 10 moles

Explanation: 180 g ÷ 18 g/mol = 10 moles.

64. In the equation 3Ca + 2Fe₂O₃ → 3CaO + 4Fe, what is the mole ratio of calcium to iron?
    a) 3:4
    b) 4:3
    c) 1:2
    d) 3:2

Answer: a) 3:4

Explanation: The ratio shows 3 moles of calcium produce 4 moles of iron.

65. If 2.5 moles of a substance have a mass of 100 g, what is its molar mass?
    a) 25 g/mol
    b) 40 g/mol
    c) 50 g/mol
    d) 20 g/mol

Answer: c) 40 g/mol

Explanation: Molar mass = mass/moles = 100 g / 2.5 moles = 40 g/mol.

66. What is the molar mass of calcium phosphate (Ca₃(PO₄)₂)?
    a) 310 g/mol
    b) 400 g/mol
    c) 215 g/mol
    d) 280 g/mol

Answer: a) 310 g/mol

Explanation: Molar mass = (3 × 40) + (2 × (31 + 4 × 16)) = 310 g/mol.

67. How many grams are in 1.5 moles of NaHCO₃ (Molar mass = 84 g/mol)?
    a) 126 g
    b) 112 g
    c) 150 g
    d) 100 g

Answer: a) 126 g

Explanation: 1.5 moles × 84 g/mol = 126 g.

68. In the reaction 2AgNO₃ + Cu → 2Ag + Cu(NO₃)₂, what is the mole ratio of silver nitrate to silver?
    a) 1:2
    b) 2:2
    c) 2:1
    d) 1:1

Answer: b) 1:1

Explanation: The coefficients indicate a 1:1 mole ratio between silver nitrate and silver.

69. In the reaction: 2H₂ + O₂ → 2H₂O, how many moles of water can be produced from 2 moles of oxygen?
    a) 2 moles
    b) 4 moles
    c) 3 moles
    d) 6 moles

Answer: b) 4 moles

Explanation: According to the reaction, 1 mole of O₂ produces 2 moles of H₂O, so 2 moles of O₂ produce 4 moles of H₂O.

70. What is the molar mass of iron(III) chloride (FeCl₃)?
    a) 130 g/mol
    b) 150 g/mol
    c) 165 g/mol
    d) 200 g/mol

Answer: c) 165 g/mol

Explanation: Molar mass = (55.85) + (3 × 35.45) = 165 g/mol.

71. How many grams are in 3 moles of Na₂CO₃ (Molar mass = 106 g/mol)?
    a) 318 g
    b) 250 g
    c) 300 g
    d) 400 g

Answer: a) 318 g

Explanation: 3 moles × 106 g/mol = 318 g.

72. In the reaction: 3H₂ + N₂ → 2NH₃, what is the mole ratio of hydrogen to ammonia?
    a) 3:2
    b) 1:2
    c) 2:3
    d) 2:1

Answer: a) 3:2

Explanation: The mole ratio shows that 3 moles of hydrogen produce 2 moles of ammonia.

73. The number of moles in 100 g of CaCO₃ (Molar mass = 100 g/mol) is:
    a) 0.5 moles
    b) 1 mole
    c) 2 moles
    d) 3 moles

Answer: b) 1 mole

Explanation: 100 g ÷ 100 g/mol = 1 mole.

74. What is the volume occupied by 5 moles of an ideal gas at STP?
    a) 112 L
    b) 134 L
    c) 100 L
    d) 112.5 L

Answer: a) 112 L

Explanation: 5 moles × 22.4 L/mole = 112 L.

75. The molar mass of calcium hydroxide (Ca(OH)₂) is:
    a) 74 g/mol
    b) 78 g/mol
    c) 64 g/mol
    d) 70 g/mol

Answer: a) 74 g/mol

Explanation: Molar mass = 40.08 + (2 × 1.01) + (2 × 16) = 74.09 g/mol.

76. How many moles are in 36 g of NH₃ (Molar mass = 17 g/mol)?
    a) 1 mole
    b) 2 moles
    c) 3 moles
    d) 4 moles

Answer: b) 2 moles

Explanation: 36 g ÷ 17 g/mol ≈ 2.12 moles.

77. In the reaction 2K + Cl₂ → 2KCl, what is the mole ratio of potassium to potassium chloride?
    a) 1:1
    b) 2:2
    c) 2:1
    d) 1:2

Answer: a) 1:1

Explanation: The coefficients indicate a 1:1 mole ratio between potassium and potassium chloride.

78. How many grams are in 0.4 moles of HCl (Molar mass = 36.5 g/mol)?
    a) 15 g
    b) 14.6 g
    c) 12 g
    d) 18 g

Answer: b) 14.6 g

Explanation: 0.4 moles × 36.5 g/mol = 14.6 g.

79. The mass of 5 moles of Na₂S (Molar mass = 78 g/mol) is:
    a) 390 g
    b) 380 g
    c) 400 g
    d) 350 g

Answer: a) 390 g

Explanation: 5 moles × 78 g/mol = 390 g.

80. How many moles are in 50 g of KBr (Molar mass = 119 g/mol)?
    a) 0.42 moles
    b) 0.35 moles
    c) 0.50 moles
    d) 0.75 moles

Answer: a) 0.42 moles

Explanation: 50 g ÷ 119 g/mol ≈ 0.42 moles.

81. In the reaction 2Na + Cl₂ → 2NaCl, how many moles of sodium are required to produce 2 moles of sodium chloride?
    a) 1 mole
    b) 2 moles
    c) 3 moles
    d) 4 moles

Answer: b) 2 moles

Explanation: The mole ratio indicates that 2 moles of sodium produce 2 moles of sodium chloride.

82. How many grams are in 0.75 moles of C₁₂H₂₂O₁₁ (Molar mass = 342 g/mol)?
    a) 150 g
    b) 250 g
    c) 250.5 g
    d) 275 g

Answer: c) 256.5 g

Explanation: 0.75 moles × 342 g/mol = 256.5 g.

83. The number of moles in 15 g of glucose (C₆H₁₂O₆) is:
    a) 0.5 moles
    b) 0.08 moles
    c) 1.0 mole
    d) 0.6 moles

Answer: b) 0.08 moles

Explanation: 15 g ÷ 180 g/mol ≈ 0.083 moles.

84. What is the molar mass of ammonium phosphate ((NH₄)₃PO₄)?
    a) 132 g/mol
    b) 115 g/mol
    c) 164 g/mol
    d) 150 g/mol

Answer: c) 164 g/mol

Explanation: Molar mass is calculated as (3 × 14) + (12 × 1) + 31 + (4 × 16) = 164 g/mol.

85. The mass of 3 moles of NH₄NO₃ (Molar mass = 80 g/mol) is:
    a) 240 g
    b) 150 g
    c) 180 g
    d) 120 g

Answer: a) 240 g

Explanation: 3 moles × 80 g/mol = 240 g.

86. How many grams are in 0.25 moles of Ca(OH)₂ (Molar mass = 74 g/mol)?
    a) 18.5 g
    b) 20 g
    c) 16 g
    d) 15 g

Answer: a) 18.5 g

Explanation: 0.25 moles × 74 g/mol = 18.5 g.

87. What is the volume occupied by 10 moles of an ideal gas at STP?
    a) 112.0 L
    b) 224.0 L
    c) 300.0 L
    d) 280.0 L

Answer: b) 224.0 L

Explanation: 10 moles × 22.4 L/mole = 224.0 L.

88. The number of moles in 50 g of NaCl (Molar mass = 58.5 g/mol) is:
    a) 0.85 moles
    b) 0.75 moles
    c) 0.68 moles
    d) 0.60 moles

Answer: a) 0.85 moles

Explanation: 50 g ÷ 58.5 g/mol ≈ 0.85 moles.

89. The molar mass of silver nitrate (AgNO₃) is:
    a) 169 g/mol
    b) 170 g/mol
    c) 160 g/mol
    d) 150 g/mol

Answer: a) 169 g/mol

Explanation: Molar mass = (107.87) + (14.01) + (3 × 16) = 169.87 g/mol.

90. In the reaction 4HCl + O₂ → 2Cl₂ + 2H₂O, how many moles of HCl are needed to produce 2 moles of Cl₂?
    a) 2 moles
    b) 4 moles
    c) 6 moles
    d) 1 mole

Answer: b) 4 moles

Explanation: The reaction shows a mole ratio of 4:2, so to produce 2 moles of Cl₂, 4 moles of HCl are required.

91. The mass of 2 moles of H₂O (Molar mass = 18 g/mol) is:
    a) 36 g
    b) 32 g
    c) 40 g
    d) 42 g

Answer: a) 36 g

Explanation: 2 moles × 18 g/mol = 36 g.

92. How many moles are in 500 g of K₂Cr₂O₇ (Molar mass = 294 g/mol)?
    a) 1.7 moles
    b) 1.5 moles
    c) 2.0 moles
    d) 3.0 moles

Answer: a) 1.7 moles

Explanation: 500 g ÷ 294 g/mol ≈ 1.70 moles.

93. The molar mass of lead(II) acetate (Pb(C₂H₃O₂)₂) is:
    a) 250 g/mol
    b) 300 g/mol
    c) 340 g/mol
    d) 400 g/mol

Answer: c) 340 g/mol

Explanation: Molar mass = 207.2 + 2 × (2 × 12.01 + 3 × 1.01 + 2 × 16) = 340.34 g/mol.

94. How many grams are in 1.5 moles of KCl (Molar mass = 74.5 g/mol)?
    a) 100 g
    b) 110 g
    c) 120 g
    d) 140 g

Answer: c) 111.75 g

Explanation: 1.5 moles × 74.5 g/mol = 111.75 g.

95. The number of moles in 200 g of C₂H₅OH (Molar mass = 46 g/mol) is:
    a) 2.5 moles
    b) 4.5 moles
    c) 3.5 moles
    d) 1.5 moles

Answer: a) 4.35 moles

Explanation: 200 g ÷ 46 g/mol ≈ 4.35 moles.

96. What is the volume occupied by 12 moles of an ideal gas at STP?
    a) 268.8 L
    b) 260.8 L
    c) 268.2 L
    d) 264.4 L

Answer: a) 268.8 L

Explanation: 12 moles × 22.4 L/mole = 268.8 L.

97. How many moles are in 80 g of MgCl₂ (Molar mass = 95.3 g/mol)?
    a) 0.75 moles
    b) 1.0 mole
    c) 1.5 moles
    d) 2.0 moles

Answer: b) 0.84 moles

Explanation: 80 g ÷ 95.3 g/mol ≈ 0.84 moles.

98. The molar mass of sodium acetate (NaC₂H₃O₂) is:
    a) 82 g/mol
    b) 75 g/mol
    c) 100 g/mol
    d) 90 g/mol

Answer: a) 82 g/mol

Explanation: Molar mass = 22.99 + (2 × 12.01) + (3 × 1.01) + (2 × 16) = 82.03 g/mol.

99. The mass of 4 moles of Na₂S (Molar mass = 78 g/mol) is:
    a) 312 g
    b) 316 g
    c) 320 g
    d) 300 g

Answer: a) 312 g

Explanation: 4 moles × 78 g/mol = 312 g.

100. How many grams are in 0.2 moles of H₂SO₄ (Molar mass = 98 g/mol)?
     a) 16 g
     b) 20 g
     c) 18 g
     d) 22 g

Answer: b) 19.6 g

Explanation: 0.2 moles × 98 g/mol = 19.6 g.

101. How many moles are in 250 g of Fe₂O₃ (Molar mass = 159.7 g/mol)?
     a) 1.5 moles
     b) 2.0 moles
     c) 1.0 mole
     d) 3.0 moles

Answer: a) 1.56 moles

Explanation: 250 g ÷ 159.7 g/mol ≈ 1.56 moles.

102. What is the volume occupied by 3 moles of an ideal gas at STP?
     a) 67.2 L
     b) 66.4 L
     c) 68.4 L
     d) 67.0 L

Answer: a) 67.2 L

Explanation: 3 moles × 22.4 L/mole = 67.2 L.

103. The molar mass of sodium sulfate (Na₂SO₄) is:
     a) 142 g/mol
     b) 150 g/mol
     c) 160 g/mol
     d) 170 g/mol

Answer: a) 142 g/mol

Explanation: Molar mass = (2 × 22.99) + 32.07 + (4 × 16) = 142.05 g/mol.

104. How many grams are in 0.5 moles of KCl (Molar mass = 74.5 g/mol)?
     a) 30 g
     b) 37.25 g
     c) 50 g
     d) 70 g

Answer: b) 37.25 g

Explanation: 0.5 moles × 74.5 g/mol = 37.25 g.

105. In the reaction 2C + O₂ → 2CO, how many moles of carbon are needed to react with 1 mole of oxygen?
     a) 1 mole
     b) 2 moles
     c) 3 moles
     d) 4 moles

Answer: b) 2 moles

Explanation: The reaction indicates that 2 moles of carbon react with 1 mole of oxygen.

106. The number of moles in 150 g of C₃H₈ (Molar mass = 44 g/mol) is:
     a) 3.0 moles
     b) 2.5 moles
     c) 4.0 moles
     d) 5.0 moles

Answer: b) 3.41 moles

Explanation: 150 g ÷ 44 g/mol ≈ 3.41 moles.

107. How many grams are in 2 moles of NH₄Cl (Molar mass = 53.5 g/mol)?
     a) 90 g
     b) 100 g
     c) 105 g
     d) 110 g

Answer: c) 107 g

Explanation: 2 moles × 53.5 g/mol = 107 g.

108. What is the molar mass of zinc sulfate (ZnSO₄)?
     a) 160 g/mol
     b) 180 g/mol
     c) 200 g/mol
     d) 220 g/mol

Answer: b) 161 g/mol

Explanation: Molar mass = 65.38 + 32.07 + (4 × 16) = 161.44 g/mol.

109. The mass of 0.75 moles of H₂O (Molar mass = 18 g/mol) is:
     a) 13.5 g
     b) 12 g
     c) 15 g
     d) 16 g

Answer: a) 13.5 g

Explanation: 0.75 moles × 18 g/mol = 13.5 g.

110. How many moles are in 60 g of AgNO₃ (Molar mass = 170 g/mol)?
     a) 0.35 moles
     b) 0.25 moles
     c) 0.40 moles
     d) 0.45 moles

Answer: b) 0.35 moles

Explanation: 60 g ÷ 170 g/mol ≈ 0.35 moles.

111. The molar mass of calcium phosphate (Ca₃(PO₄)₂) is:
     a) 100 g/mol
     b) 220 g/mol
     c) 310 g/mol
     d) 250 g/mol

Answer: c) 310 g/mol

Explanation: Molar mass = (3 × 40.08) + (2 × (30.97 + (4 × 16))) = 310.18 g/mol.

112. How many grams are in 1.5 moles of H₂SO₄ (Molar mass = 98 g/mol)?
     a) 147 g
     b) 150 g
     c) 120 g
     d) 130 g

Answer: a) 147 g

Explanation: 1.5 moles × 98 g/mol = 147 g.

113. In the reaction: N₂ + 3H₂ → 2NH₃, how many moles of hydrogen are needed for 1 mole of nitrogen?
     a) 1 mole
     b) 2 moles
     c) 3 moles
     d) 4 moles

Answer: c) 3 moles

Explanation: The stoichiometry shows that 1 mole of N₂ requires 3 moles of H₂.

114. The volume occupied by 4 moles of an ideal gas at STP is:
     a) 100 L
     b) 89.6 L
     c) 90 L
     d) 89.7 L

Answer: a) 89.6 L

Explanation: 4 moles × 22.4 L/mole = 89.6 L.

115. The number of moles in 80 g of Ca(OH)₂ (Molar mass = 74 g/mol) is:
     a) 1.08 moles
     b) 1.15 moles
     c) 2.00 moles
     d) 0.90 moles

Answer: a) 1.08 moles

Explanation: 80 g ÷ 74 g/mol ≈ 1.08 moles.

116. How many grams are in 0.8 moles of NaHCO₃ (Molar mass = 84 g/mol)?
     a) 66.4 g
     b) 65 g
     c) 70 g
     d) 72 g

Answer: a) 67.2 g

Explanation: 0.8 moles × 84 g/mol = 67.2 g.

117. The molar mass of sulfuric acid (H₂SO₄) is:
     a) 96 g/mol
     b) 98 g/mol
     c) 100 g/mol
     d) 95 g/mol

Answer: b) 98 g/mol

Explanation: Molar mass = 2 × 1.01 + 32.07 + 4 × 16.00 = 98.09 g/mol.

118. The mass of 1 mole of CO₂ (Molar mass = 44 g/mol) is:
     a) 40 g
     b) 42 g
     c) 44 g
     d) 46 g

Answer: c) 44 g

Explanation: 1 mole × 44 g/mol = 44 g.

119. How many moles are in 90 g of H₂O₂ (Molar mass = 34 g/mol)?
     a) 2.5 moles
     b) 3.0 moles
     c) 1.5 moles
     d) 2.0 moles

Answer: b) 2.65 moles

Explanation: 90 g ÷ 34 g/mol ≈ 2.65 moles.

120. The molar mass of potassium hydroxide (KOH) is:
     a) 100 g/mol
     b) 92 g/mol
     c) 80 g/mol
     d) 75 g/mol

Answer: b) 56.11 g/mol

Explanation: Molar mass = 39.10 + 16.00 + 1.01 = 56.11 g/mol.

121. The molar mass of potassium permanganate (KMnO₄) is:
     a) 158 g/mol
     b) 160 g/mol
     c) 170 g/mol
     d) 180 g/mol

Answer: a) 158 g/mol

Explanation: Molar mass = 39.10 + 54.94 + (4 × 16) = 158.04 g/mol.

122. How many grams are in 2.5 moles of NaCl (Molar mass = 58.5 g/mol)?
     a) 130 g
     b) 140 g
     c) 145 g
     d) 150 g

Answer: a) 146.25 g

Explanation: 2.5 moles × 58.5 g/mol = 146.25 g.

123. The number of moles in 1 g of NaCl is:
     a) 0.01 moles
     b) 0.02 moles
     c) 0.03 moles
     d) 0.04 moles

Answer: b) 0.017 moles

Explanation: 1 g ÷ 58.5 g/mol ≈ 0.017 moles.

124. The mass of 3 moles of H₂ (Molar mass = 2 g/mol) is:
     a) 4 g
     b) 5 g
     c) 6 g
     d) 8 g

Answer: c) 6 g

Explanation: 3 moles × 2 g/mol = 6 g.

125. In the reaction: 2H₂ + O₂ → 2H₂O, how many moles of water are produced from 2 moles of hydrogen?
     a) 1 mole
     b) 2 moles
     c) 3 moles
     d) 4 moles

Answer: b) 2 moles

Explanation: The stoichiometry indicates that 2 moles of H₂ produce 2 moles of H₂O.

126. The volume occupied by 10 moles of an ideal gas at STP is:
     a) 200 L
     b) 220 L
     c) 240 L
     d) 224 L

Answer: a) 224 L

Explanation: 10 moles × 22.4 L/mole = 224 L.

127. How many grams are in 0.4 moles of C₆H₁₂O₆ (Molar mass = 180 g/mol)?
     a) 60 g
     b) 70 g
     c) 72 g
     d) 80 g

Answer: c) 72 g

Explanation: 0.4 moles × 180 g/mol = 72 g.

128. The molar mass of barium chloride (BaCl₂) is:
     a) 137 g/mol
     b) 165 g/mol
     c) 200 g/mol
     d) 250 g/mol

Answer: b) 208 g/mol

Explanation: Molar mass = 137.33 + (2 × 35.45) = 208.23 g/mol.

129. The number of moles in 300 g of CaCO₃ (Molar mass = 100 g/mol) is:
     a) 1.0 mole
     b) 2.0 moles
     c) 3.0 moles
     d) 4.0 moles

Answer: b) 3.0 moles

Explanation: 300 g ÷ 100 g/mol = 3.0 moles.

130. How many moles are in 50 g of Al₂O₃ (Molar mass = 102 g/mol)?
     a) 0.4 moles
     b) 0.5 moles
     c) 0.6 moles
     d) 0.7 moles

Answer: b) 0.49 moles

Explanation: 50 g ÷ 102 g/mol ≈ 0.49 moles.

131. The molar mass of ammonium sulfate ((NH₄)₂SO₄) is:
     a) 132 g/mol
     b) 150 g/mol
     c) 180 g/mol
     d) 100 g/mol

Answer: a) 132 g/mol

Explanation: Molar mass = (2 × 14.01) + (8 × 1.01) + 32.07 + (4 × 16) = 132.14 g/mol.

132. How many grams are in 0.6 moles of FeCl₃ (Molar mass = 162.2 g/mol)?
     a) 90 g
     b) 98 g
     c) 100 g
     d) 110 g

Answer: b) 97.32 g

Explanation: 0.6 moles × 162.2 g/mol = 97.32 g.

133. In the reaction: 2Fe + 3Cl₂ → 2FeCl₃, how many moles of Cl₂ are required for 4 moles of Fe?
     a) 3 moles
     b) 4 moles
     c) 5 moles
     d) 6 moles

Answer: d) 6 moles

Explanation: The ratio shows that 3 moles of Cl₂ are needed for 2 moles of Fe, so 4 moles of Fe require 6 moles of Cl₂.

134. The mass of 0.75 moles of K₂SO₄ (Molar mass = 174.3 g/mol) is:
     a) 120 g
     b) 130 g
     c) 140 g
     d) 130.73 g

Answer: d) 130.73 g

Explanation: 0.75 moles × 174.3 g/mol = 130.73 g.

135. The number of moles in 25 g of C₂H₄ (Molar mass = 28 g/mol) is:
     a) 0.5 moles
     b) 1.0 mole
     c) 2.0 moles
     d) 3.0 moles

Answer: a) 0.89 moles

Explanation: 25 g ÷ 28 g/mol ≈ 0.89 moles.

136. The molar mass of copper(II) sulfate (CuSO₄) is:
     a) 158 g/mol
     b) 160 g/mol
     c) 162 g/mol
     d) 164 g/mol

Answer: a) 159.61 g/mol

Explanation: Molar mass = 63.55 + 32.07 + (4 × 16) = 159.61 g/mol.

137. How many grams are in 2 moles of CH₄ (Molar mass = 16 g/mol)?
     a) 30 g
     b) 32 g
     c) 34 g
     d) 36 g

Answer: b) 32 g

Explanation: 2 moles × 16 g/mol = 32 g.

138. How many moles are in 100 g of NaOH (Molar mass = 40 g/mol)?
     a) 2.0 moles
     b) 1.5 moles
     c) 2.5 moles
     d) 3.0 moles

Answer: a) 2.5 moles

Explanation: 100 g ÷ 40 g/mol = 2.5 moles.

139. The molar mass of strontium chloride (SrCl₂) is:
     a) 136 g/mol
     b) 150 g/mol
     c) 180 g/mol
     d) 200 g/mol

Answer: c) 158.5 g/mol

Explanation: Molar mass = 87.62 + (2 × 35.45) = 158.52 g/mol.

140. The mass of 0.5 moles of H₂SO₄ (Molar mass = 98 g/mol) is:
     a) 48 g
     b) 49 g
     c) 50 g
     d) 49 g

Answer: b) 49 g

Explanation: 0.5 moles × 98 g/mol = 49 g.

141. How many grams are in 3.2 moles of C₆H₁₂O₆ (Molar mass = 180 g/mol)?
     a) 500 g
     b) 540 g
     c) 580 g
     d) 600 g

Answer: b) 576 g

Explanation: 3.2 moles × 180 g/mol = 576 g.

142. The number of moles in 600 g of Na₂CO₃ (Molar mass = 106 g/mol) is:
     a) 5.0 moles
     b) 6.0 moles
     c) 7.0 moles
     d) 8.0 moles

Answer: a) 5.66 moles

Explanation: 600 g ÷ 106 g/mol ≈ 5.66 moles.

143. The molar mass of sodium thiosulfate (Na₂S₂O₃) is:
     a) 230 g/mol
     b) 250 g/mol
     c) 260 g/mol
     d) 270 g/mol

Answer: a) 158 g/mol

Explanation: Molar mass = (2 × 22.99) + (2 × 32.07) + (3 × 16) = 158.11 g/mol.

144. The volume occupied by 5 moles of an ideal gas at STP is:
     a) 112 L
     b) 120 L
     c) 140 L
     d) 112 L

Answer: a) 112 L

Explanation: 5 moles × 22.4 L/mole = 112 L.

145. The mass of 1.5 moles of glucose (C₆H₁₂O₆, Molar mass = 180 g/mol) is:
     a) 250 g
     b) 270 g
     c) 280 g
     d) 300 g

Answer: c) 270 g

Explanation: 1.5 moles × 180 g/mol = 270 g.

146. How many moles are in 450 g of Ca(OH)₂ (Molar mass = 74 g/mol)?
     a) 4.0 moles
     b) 5.0 moles
     c) 6.0 moles
     d) 7.0 moles

Answer: a) 6.08 moles

Explanation: 450 g ÷ 74 g/mol ≈ 6.08 moles.

147. The molar mass of lithium carbonate (Li₂CO₃) is:
     a) 90 g/mol
     b) 100 g/mol
     c) 120 g/mol
     d) 130 g/mol

Answer: a) 74 g/mol

Explanation: Molar mass = (2 × 6.94) + 12.01 + (3 × 16) = 73.89 g/mol.

148. How many grams are in 0.25 moles of CCl₄ (Molar mass = 153.8 g/mol)?
     a) 37.3 g
     b) 40 g
     c) 42 g
     d) 45 g

Answer: a) 38.45 g

Explanation: 0.25 moles × 153.8 g/mol = 38.45 g.

149. The mass of 3 moles of magnesium sulfate (MgSO₄, Molar mass = 120 g/mol) is:
     a) 360 g
     b) 370 g
     c) 380 g
     d) 390 g

Answer: a) 360 g

Explanation: 3 moles × 120 g/mol = 360 g.

150. How many moles are in 72 g of O₂ (Molar mass = 32 g/mol)?
     a) 1.0 mole
     b) 2.0 moles
     c) 2.5 moles
     d) 3.0 moles

Answer: b) 2.25 moles

Explanation: 72 g ÷ 32 g/mol = 2.25 moles.