Moles & Molar Mass (College Board AP® Chemistry)

Exam Questions

9 mins9 questions
11 mark

How many moles of ethane (C2H6) are there in 5.3 g of ethane?

  • 1.8 x 10-1 mol

  • 5.7 mol

  • 18 mol

  • 57 mol

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21 mark

To two decimal places, what is the molar mass of (NH4)2SO4?

  • 114.10 gmol-1

  • 132.14 gmol-1

  • 118.13 gmol-1

  • 160.16 gmol-1

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31 mark

The mass of one atom of calcium is

  • 3.32 x 1023 g

  • 6.66 x 10-23 g

  • 2.41 x 1025 g

  • 1.20 x 1025 g

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41 mark

How many molecules of propane (C3H8) does a 23.0 g sample of propane contain?

  • 8.66 x 10-25

  • 1.15 x 1024

  • 3.74 x 1023

  • 3.14 x 1023

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51 mark

How many atoms of iron are in 1 mole of Fe2O3

  • 6.022 x 1023

  • 1.807 x 1023

  • 1.204 x 1024

  • 3.011 x 1024

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61 mark

The sample that contains the greatest number of moles is

  • 1 g of methanal, CH2O

  • 2 g of carbon dioxide, CO2

  • 3 g of sulfur, S6

  • 4 g of bromine, Br2

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71 mark

The substance that contains the greatest number of moles is

  • 3.00 g of ammonia (NH3)

  • 3.00 g of chloromethane (CH3Cl)

  • 4.00 g of hydrogen sulfide (H2S)

  • 3.50 g of hydrogen chloride (HCl)

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81 mark


How many moles are in 860 atoms of gold?

  • 5.18 x 1026 mols

  • 1.43 x 10-21 mols

  • 4.37 mols

  • 0.23 mols

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91 mark

What is the mass of 8.54 × 1020 particles of Cl2?

  • 0.05 g

  • 2.00 x 10-5 g

  • 1.42 x 10-3 g

  • 0.10 g

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