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Moles & Mass Worksheets — m = n × M (Free Printable)

The mole is chemistry’s counting unit, and the bridge to mass is the molar mass M (g/mol). These worksheets drill m = n × M and its inverse for common substances (water, salt, carbon dioxide, oxygen, methane), with real molar masses. Students can verify any answer against the UnitFig molar-mass and unit converters.

Sample problems (new ones below)

Moles in 197 g CH₄ (M = 16.04 g/mol)? → 12.282 molMass of 4 mol O₂ (M = 32 g/mol)? → 128.00 gMass of 8 mol CO₂ (M = 44.01 g/mol)? → 352.08 gMass of 8 mol H₂O (M = 18.015 g/mol)? → 144.12 gMass of 7 mol NaCl (M = 58.44 g/mol)? → 409.08 gMass of 3 mol CH₄ (M = 16.04 g/mol)? → 48.12 gMass of 7 mol CO₂ (M = 44.01 g/mol)? → 308.07 gMoles in 184 g CO₂ (M = 44.01 g/mol)? → 4.181 molMass of 3 mol O₂ (M = 32 g/mol)? → 96.00 gMoles in 37 g O₂ (M = 32 g/mol)? → 1.156 molMass of 10 mol O₂ (M = 32 g/mol)? → 320.00 gMoles in 187 g CO₂ (M = 44.01 g/mol)? → 4.249 molMoles in 18 g H₂O (M = 18.015 g/mol)? → 0.999 molMass of 5 mol CH₄ (M = 16.04 g/mol)? → 80.20 gMoles in 189 g NaCl (M = 58.44 g/mol)? → 3.234 molMass of 7 mol O₂ (M = 32 g/mol)? → 224.00 gMass of 8 mol CH₄ (M = 16.04 g/mol)? → 128.32 gMoles in 128 g NaCl (M = 58.44 g/mol)? → 2.190 molMoles in 194 g CO₂ (M = 44.01 g/mol)? → 4.408 molMass of 10 mol CH₄ (M = 16.04 g/mol)? → 160.40 gMass of 3 mol CO₂ (M = 44.01 g/mol)? → 132.03 gMoles in 191 g CH₄ (M = 16.04 g/mol)? → 11.908 molMass of 9 mol H₂O (M = 18.015 g/mol)? → 162.13 gMoles in 138 g O₂ (M = 32 g/mol)? → 4.313 mol

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Chemistry moles
Name: _______________  ·  Date: _______________
unitfig.com/math-worksheets/chemistry-moles · free printable
1.Moles in 38 g O₂ (M = 32 g/mol)?
2.Moles in 185 g CO₂ (M = 44.01 g/mol)?
3.Moles in 119 g CH₄ (M = 16.04 g/mol)?
4.Moles in 139 g CO₂ (M = 44.01 g/mol)?
5.Moles in 107 g H₂O (M = 18.015 g/mol)?
6.Moles in 59 g H₂O (M = 18.015 g/mol)?
7.Mass of 7 mol NaCl (M = 58.44 g/mol)?
8.Moles in 159 g NaCl (M = 58.44 g/mol)?
9.Mass of 3 mol NaCl (M = 58.44 g/mol)?
10.Mass of 6 mol H₂O (M = 18.015 g/mol)?
11.Mass of 1 mol CH₄ (M = 16.04 g/mol)?
12.Mass of 3 mol O₂ (M = 32 g/mol)?
13.Moles in 126 g CH₄ (M = 16.04 g/mol)?
14.Mass of 8 mol H₂O (M = 18.015 g/mol)?
15.Mass of 8 mol CH₄ (M = 16.04 g/mol)?
16.Mass of 4 mol NaCl (M = 58.44 g/mol)?
17.Mass of 6 mol CH₄ (M = 16.04 g/mol)?
18.Moles in 122 g NaCl (M = 58.44 g/mol)?
19.Mass of 9 mol O₂ (M = 32 g/mol)?
20.Moles in 14 g CO₂ (M = 44.01 g/mol)?
21.Moles in 110 g CO₂ (M = 44.01 g/mol)?
22.Moles in 80 g NaCl (M = 58.44 g/mol)?
23.Mass of 10 mol O₂ (M = 32 g/mol)?
24.Moles in 86 g NaCl (M = 58.44 g/mol)?
Answer Key
1. 1.188 mol(Use m = n × M or n = m / M (molar mass 32 g/mol).)
2. 4.204 mol(Use m = n × M or n = m / M (molar mass 44.01 g/mol).)
3. 7.419 mol(Use m = n × M or n = m / M (molar mass 16.04 g/mol).)
4. 3.158 mol(Use m = n × M or n = m / M (molar mass 44.01 g/mol).)
5. 5.939 mol(Use m = n × M or n = m / M (molar mass 18.015 g/mol).)
6. 3.275 mol(Use m = n × M or n = m / M (molar mass 18.015 g/mol).)
7. 409.08 g(Use m = n × M or n = m / M (molar mass 58.44 g/mol).)
8. 2.721 mol(Use m = n × M or n = m / M (molar mass 58.44 g/mol).)
9. 175.32 g(Use m = n × M or n = m / M (molar mass 58.44 g/mol).)
10. 108.09 g(Use m = n × M or n = m / M (molar mass 18.015 g/mol).)
11. 16.04 g(Use m = n × M or n = m / M (molar mass 16.04 g/mol).)
12. 96.00 g(Use m = n × M or n = m / M (molar mass 32 g/mol).)
13. 7.855 mol(Use m = n × M or n = m / M (molar mass 16.04 g/mol).)
14. 144.12 g(Use m = n × M or n = m / M (molar mass 18.015 g/mol).)
15. 128.32 g(Use m = n × M or n = m / M (molar mass 16.04 g/mol).)
16. 233.76 g(Use m = n × M or n = m / M (molar mass 58.44 g/mol).)
17. 96.24 g(Use m = n × M or n = m / M (molar mass 16.04 g/mol).)
18. 2.088 mol(Use m = n × M or n = m / M (molar mass 58.44 g/mol).)
19. 288.00 g(Use m = n × M or n = m / M (molar mass 32 g/mol).)
20. 0.318 mol(Use m = n × M or n = m / M (molar mass 44.01 g/mol).)
21. 2.499 mol(Use m = n × M or n = m / M (molar mass 44.01 g/mol).)
22. 1.369 mol(Use m = n × M or n = m / M (molar mass 58.44 g/mol).)
23. 320.00 g(Use m = n × M or n = m / M (molar mass 32 g/mol).)
24. 1.472 mol(Use m = n × M or n = m / M (molar mass 58.44 g/mol).)

Teaching tips for moles

  • •Write the triangle: mass (g) = moles (mol) × molar mass (g/mol). Cover one quantity to reveal the formula for the other.
  • •Use the periodic-table molar masses: H₂O ≈ 18.02, NaCl ≈ 58.44, CO₂ ≈ 44.01, O₂ = 32.0, CH₄ ≈ 16.04 g/mol.
  • •Always carry the unit through: mol × g/mol = g. The unit itself proves the formula was applied correctly.

Common mistakes to watch for

✗ Dividing when you should multiply (or vice versa).
✓ mass = moles × M (multiply); moles = mass ÷ M (divide). The unit check mol × g/mol = g confirms the direction.
✗ Using the wrong molar mass.
✓ Each substance has its own M from the periodic table. These sheets state M on every problem so the student practices the right conversion, not memorizing M.

Check your answers with the tools

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Grade & standards alignment

These moles worksheets target the Grades 9–10 band of the Common Core State Standards for Mathematics (CCSSM). The relevant CCSS math domains are:

Physical Science — Matter & Stoichiometry

Source: Common Core State Standards for Mathematics (2010). National Governors Association Center for Best Practices (NGA Center) & Council of Chief State School Officers (CCSSO). Retrieved 2026-08-11 from https://www.corestandards.org/Math/.

The CCSSM are public, open-license standards; this alignment is provided for planning and is not an official endorsement by the standards authors.

How these worksheets are built (accuracy & trust)

  • •Problems are generated by a deterministic engine using exact integer and rational arithmetic — answers are reduced to lowest terms and never rely on floating-point rounding, so they match the matching UnitFig converter.
  • •Grade presets follow the CCSSM progression above; pick a grade to get age-appropriate number ranges.
  • •Content is reviewed for accuracy and refreshed each year (2026). Worksheet copy and examples are original and written for classroom use.

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Frequently Asked Questions

What is the formula linking moles and mass?

mass (g) = moles (mol) × molar mass M (g/mol). The inverse is moles = mass ÷ M. The worksheet states M for each substance.

What molar masses are used?

H₂O 18.015, NaCl 58.44, CO₂ 44.01, O₂ 32.0, CH₄ 16.04 g/mol — standard periodic-table values.

What grade is stoichiometry introduced?

The mole and mass relationships appear in grade 9–10 high-school chemistry.

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Last Updated 2026 | Problems are algorithm-generated with the exact NIST/SI constants used by UnitFig converters. Answers are computed programmatically and can be verified with the matching converter.