Moles and Molar Mass - AP Chemistry

1. How many atoms are in 1 mole of carbon?

   $6.022 \times 10^{23}$ atoms. One mole contains Avogadro's number of atoms.

2. Find the number of moles in 75 g of C₆H₆.

   0.96 moles. 75 g ÷ 78.12 g/mol = 0.96 mol

3. What is the formula for number of particles?

   Particles = moles $\times$ Avogadro's number. Converts moles to individual particles.

4. What is the molar mass of CH₄?

   16.04 g/mol. C = 12.01, H = 1.01: $12.01 + (4 \times 1.01)$

5. Find the number of moles in 90 g of C₂H₅OH.

   1.96 moles. 90 g ÷ 46.08 g/mol = 1.96 mol

6. Find the number of moles in 75 g of C₆H₆.

   0.96 moles. 75 g ÷ 78.12 g/mol = 0.96 mol

7. Find the number of moles in 90 g of C₂H₅OH.

   1.96 moles. 90 g ÷ 46.08 g/mol = 1.96 mol

8. What is the molar mass of H₂O?

   18.02 g/mol. H = 1.01, O = 16.00: $(2 \times 1.01) + 16.00$

9. Convert 3 moles of Na to grams.

   68.97 grams. 3 mol × 22.99 g/mol = 68.97 g

10. Calculate moles in 50 g of CO.

    1.79 moles. 50 g ÷ 28.01 g/mol = 1.79 mol

11. What is the molar mass of Fe₂O₃?

    159.69 g/mol. Fe = 55.85, O = 16.00: $(2 \times 55.85) + (3 \times 16.00)$

12. State Avogadro's number.

    $6.022 \times 10^{23}$. The number of particles in one mole.

13. What is the molar mass of Al₂O₃?

    101.96 g/mol. Al = 26.98, O = 16.00: $(2 \times 26.98) + (3 \times 16.00)$

14. Determine moles in 4.5 grams of H₂.

    2.23 moles. 4.5 g ÷ 2.02 g/mol = 2.23 mol

15. Convert 3 moles of Na to grams.

    68.97 grams. 3 mol × 22.99 g/mol = 68.97 g

16. Calculate number of molecules in 2 moles of CO₂.

    $1.204 \times 10^{24}$ molecules. 2 mol × $6.022 \times 10^{23}$ = $1.204 \times 10^{24}$

17. What is the formula for molar mass?

    Molar mass = mass / moles. Rearranged from moles = mass/molar mass.

18. How many grams are in 0.5 moles of NaCl?

    29.22 grams. 0.5 mol × 58.44 g/mol = 29.22 g

19. Calculate mass of 0.75 moles of KBr.

    89.25 grams. 0.75 mol × 119.0 g/mol = 89.25 g

20. What is molar mass?

    The mass of one mole of a substance, in g/mol. Connects mass to amount of substance.

21. Calculate mass of 2 moles of H₂SO₄.

    196.16 grams. 2 mol × 98.08 g/mol = 196.16 g

22. Calculate the moles in 32 grams of O₂.

    1 mole. 32 g ÷ 32.00 g/mol = 1 mol

23. Determine moles in 4.5 grams of H₂.

    2.23 moles. 4.5 g ÷ 2.02 g/mol = 2.23 mol

24. Determine moles in 150 g of H₂O.

    8.33 moles. 150 g ÷ 18.02 g/mol = 8.33 mol

25. How many molecules in 0.25 moles of H₂O?

    $1.506 \times 10^{23}$ molecules. 0.25 mol × $6.022 \times 10^{23}$ = $1.506 \times 10^{23}$

26. What is the molar mass of Fe₂O₃?

    159.69 g/mol. Fe = 55.85, O = 16.00: $(2 \times 55.85) + (3 \times 16.00)$

27. Convert 3 moles of Na to grams.

    68.97 grams. 3 mol × 22.99 g/mol = 68.97 g

28. What is the molar mass of C₂H₄?

    28.05 g/mol. C = 12.01, H = 1.01: $(2 \times 12.01) + (4 \times 1.01)$

29. How many grams in 0.2 moles of H₂SO₄?

    19.62 grams. 0.2 mol × 98.08 g/mol = 19.62 g

30. Find the number of moles in 90 g of C₂H₅OH.

    1.96 moles. 90 g ÷ 46.08 g/mol = 1.96 mol

31. How many grams are in 0.5 moles of NaCl?

    29.22 grams. 0.5 mol × 58.44 g/mol = 29.22 g

32. Calculate moles in 50 g of CO.

    1.79 moles. 50 g ÷ 28.01 g/mol = 1.79 mol

33. What is the molar mass of H₂O?

    18.02 g/mol. H = 1.01, O = 16.00: $(2 \times 1.01) + 16.00$

34. Find the molar mass of C₃H₈.

    44.10 g/mol. C = 12.01, H = 1.01: $(3 \times 12.01) + (8 \times 1.01)$

35. How many moles are in 18 grams of water?

    1 mole. 18 g ÷ 18.02 g/mol = 1 mol

36. How many molecules in 0.25 moles of H₂O?

    $1.506 \times 10^{23}$ molecules. 0.25 mol × $6.022 \times 10^{23}$ = $1.506 \times 10^{23}$

37. What is the molar mass of C₂H₄?

    28.05 g/mol. C = 12.01, H = 1.01: $(2 \times 12.01) + (4 \times 1.01)$

38. What is the molar mass of CO₂?

    44.01 g/mol. C = 12.01, O = 16.00: $12.01 + (2 \times 16.00)$

39. Calculate mass of 0.75 moles of KBr.

    89.25 grams. 0.75 mol × 119.0 g/mol = 89.25 g

40. What is the molar mass of NH₃?

    17.03 g/mol. N = 14.01, H = 1.01: $14.01 + (3 \times 1.01)$

41. How many moles are in 18 grams of water?

    1 mole. 18 g ÷ 18.02 g/mol = 1 mol

42. How is molar mass calculated?

    Sum of atomic masses in a molecule, in g/mol. Add all atomic masses from the formula.

43. How many atoms are in 1 mole of carbon?

    $6.022 \times 10^{23}$ atoms. One mole contains Avogadro's number of atoms.

44. What is the molar mass of CH₄?

    16.04 g/mol. C = 12.01, H = 1.01: $12.01 + (4 \times 1.01)$

45. What is the molar mass of NaCl?

    58.44 g/mol. Na = 22.99, Cl = 35.45: $22.99 + 35.45$

46. What is the molar mass of NaCl?

    58.44 g/mol. Na = 22.99, Cl = 35.45: $22.99 + 35.45$

47. How many molecules in 0.25 moles of H₂O?

    $1.506 \times 10^{23}$ molecules. 0.25 mol × $6.022 \times 10^{23}$ = $1.506 \times 10^{23}$

48. Calculate mass of 2 moles of H₂SO₄.

    196.16 grams. 2 mol × 98.08 g/mol = 196.16 g

49. What is the molar mass of H₃PO₄?

    97.99 g/mol. H = 1.01, P = 30.97, O = 16.00: $(3 \times 1.01) + 30.97 + (4 \times 16.00)$

50. Calculate number of molecules in 2 moles of CO₂.

    $1.204 \times 10^{24}$ molecules. 2 mol × $6.022 \times 10^{23}$ = $1.204 \times 10^{24}$

51. What is the molar mass of H₂O?

    18.02 g/mol. H = 1.01, O = 16.00: $(2 \times 1.01) + 16.00$

52. What is the molar mass of Al₂O₃?

    101.96 g/mol. Al = 26.98, O = 16.00: $(2 \times 26.98) + (3 \times 16.00)$

53. What is the molar mass of NH₃?

    17.03 g/mol. N = 14.01, H = 1.01: $14.01 + (3 \times 1.01)$

54. Calculate the moles in 32 grams of O₂.

    1 mole. 32 g ÷ 32.00 g/mol = 1 mol

55. Calculate the moles in 32 grams of O₂.

    1 mole. 32 g ÷ 32.00 g/mol = 1 mol

56. What is the molar mass of C₂H₄?

    28.05 g/mol. C = 12.01, H = 1.01: $(2 \times 12.01) + (4 \times 1.01)$

57. How many grams in 0.2 moles of H₂SO₄?

    19.62 grams. 0.2 mol × 98.08 g/mol = 19.62 g

58. What is the definition of a mole in chemistry?

    A mole is $6.022 \times 10^{23}$ particles of a substance. Fundamental unit of chemical quantity.

59. How many grams in 0.2 moles of H₂SO₄?

    19.62 grams. 0.2 mol × 98.08 g/mol = 19.62 g

60. Find the mass of 3 moles of HCl.

    109.5 grams. 3 mol × 36.5 g/mol = 109.5 g

61. What is the molar mass of H₃PO₄?

    97.99 g/mol. H = 1.01, P = 30.97, O = 16.00: $(3 \times 1.01) + 30.97 + (4 \times 16.00)$

62. What is molar mass?

    The mass of one mole of a substance, in g/mol. Connects mass to amount of substance.

63. Find the molar mass of C₃H₈.

    44.10 g/mol. C = 12.01, H = 1.01: $(3 \times 12.01) + (8 \times 1.01)$

64. What is the molar mass of $MgCl_2$?

    95.21 g/mol. Mg = 24.31, Cl = 35.45: $24.31 + (2 \times 35.45)$

65. How is moles of a substance calculated from mass?

    Moles = mass / molar mass. Divides mass by molar mass for conversion.

66. Calculate mass of 2 moles of H₂SO₄.

    196.16 grams. 2 mol × 98.08 g/mol = 196.16 g

67. What is molar mass?

    The mass of one mole of a substance, in g/mol. Connects mass to amount of substance.

68. What is the molar mass of KCl?

    74.55 g/mol. K = 39.10, Cl = 35.45: $39.10 + 35.45$

69. Determine moles in 150 g of H₂O.

    8.33 moles. 150 g ÷ 18.02 g/mol = 8.33 mol

70. What is the molar mass of Al₂O₃?

    101.96 g/mol. Al = 26.98, O = 16.00: $(2 \times 26.98) + (3 \times 16.00)$

71. Convert 5 moles of Fe to grams.

    279.5 grams. 5 mol × 55.9 g/mol = 279.5 g

72. Calculate mass of 0.75 moles of KBr.

    89.25 grams. 0.75 mol × 119.0 g/mol = 89.25 g

73. Find the molar mass of C₃H₈.

    44.10 g/mol. C = 12.01, H = 1.01: $(3 \times 12.01) + (8 \times 1.01)$

74. Determine moles in 4.5 grams of H₂.

    2.23 moles. 4.5 g ÷ 2.02 g/mol = 2.23 mol

75. How is moles of a substance calculated from mass?

    Moles = mass / molar mass. Divides mass by molar mass for conversion.

76. What is the formula for number of particles?

    Particles = moles $\times$ Avogadro's number. Converts moles to individual particles.

77. What is the definition of a mole in chemistry?

    A mole is $6.022 \times 10^{23}$ particles of a substance. Fundamental unit of chemical quantity.

78. What is the formula for number of particles?

    Particles = moles $\times$ Avogadro's number. Converts moles to individual particles.

79. What is the molar mass of NH₃?

    17.03 g/mol. N = 14.01, H = 1.01: $14.01 + (3 \times 1.01)$

80. How many atoms are in 1 mole of carbon?

    $6.022 \times 10^{23}$ atoms. One mole contains Avogadro's number of atoms.

81. How many moles are in 100 grams of NaOH?

    2.5 moles. 100 g ÷ 40.00 g/mol = 2.5 mol

82. How many moles are in 100 grams of NaOH?

    2.5 moles. 100 g ÷ 40.00 g/mol = 2.5 mol

83. What is the molar mass of $MgCl_2$?

    95.21 g/mol. $Mg = 24.31$, $Cl = 35.45$: $24.31 + (2 \times 35.45)$

84. How many grams are in 0.5 moles of NaCl?

    29.22 grams. 0.5 mol × 58.44 g/mol = 29.22 g

85. What is the molar mass of CH₄?

    16.04 g/mol. C = 12.01, H = 1.01: $12.01 + (4 \times 1.01)$

86. Find the mass of 3 moles of HCl.

    109.5 grams. 3 mol × 36.5 g/mol = 109.5 g

87. How many moles are in 100 grams of NaOH?

    2.5 moles. 100 g ÷ 40.00 g/mol = 2.5 mol

88. Calculate number of molecules in 2 moles of CO₂.

    $1.204 \times 10^{24}$ molecules. 2 mol × $6.022 \times 10^{23}$ = $1.204 \times 10^{24}$

89. Calculate moles from 200 g of CaCO₃.

    2 moles. 200 g ÷ 100.09 g/mol = 2.00 mol

90. What is the definition of a mole in chemistry?

    A mole is $6.022 \times 10^{23}$ particles of a substance. Fundamental unit of chemical quantity.

91. What is the molar mass of KCl?

    74.55 g/mol. K = 39.10, Cl = 35.45: $39.10 + 35.45$

92. What is the molar mass of Fe₂O₃?

    159.69 g/mol. Fe = 55.85, O = 16.00: $(2 \times 55.85) + (3 \times 16.00)$

93. Find the mass of 3 moles of HCl.

    109.5 grams. 3 mol × 36.5 g/mol = 109.5 g

94. How many moles are in 18 grams of water?

    1 mole. 18 g ÷ 18.02 g/mol = 1 mol

95. What is the molar mass of C₆H₁₂O₆?

    180.18 g/mol. Glucose: $(6 \times 12.01) + (12 \times 1.01) + (6 \times 16.00)$

96. State Avogadro's number.

    $6.022 \times 10^{23}$. The number of particles in one mole.

97. What is the molar mass of KCl?

    74.55 g/mol. K = 39.10, Cl = 35.45: $39.10 + 35.45$

98. What is the molar mass of MgCl₂?

    95.21 g/mol. Mg = 24.31, Cl = 35.45: $24.31 + (2 \times 35.45)$

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