Gas volume and moles at standard conditions

Answer Key - Grade 10 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   A balloon at STP (0 °C, 1 atm) holds 44.8 L of carbon dioxide. One mole of gas fills 22.4 L there. How many moles is that, Ari?

   2 mol
2. 2.

   What volume does 1 mol of any gas fill at 0 °C and 1 atm, Jun?

   • 44.8 L
   • 22.4 L
   • 22.7 L
3. 3.

   At STP, which fills more space: 1 mol of CO₂ or 1 mol of O₂, Luz?

   • The O₂, since its molecules are lighter
   • Neither: each fills 22.4 L
   • The CO₂, since its molecules are heavier
4. 4.

   Why do 1 mol of O₂ and 1 mol of CO₂ fill the same volume at STP, Milo?

   • Gas particles are far apart, so their size barely matters
   • Both gases have the same molar mass
   • Heavier molecules squeeze closer together
5. 5.

   On the mole map, which step turns liters of a gas at STP into moles, Noah?

   • Divide by 6.022 × 10²³
   • Multiply by 22.4 L/mol
   • Divide by 22.4 L/mol
6. 6.

   On the mole map, which step turns moles of a gas at STP into liters, Pia?

   • Divide by 22.4 L/mol
   • Multiply by 22.4 L/mol
   • Multiply by the molar mass
7. 7.

   Which setup changes 33.6 L of CO₂ at STP into moles, Ren?

   • 33.6 L × (22.4 L ÷ 1 mol)
   • 33.6 L × (1 mol ÷ 22.4 L)
   • 33.6 L ÷ (6.022 × 10²³)
8. 8.

   What does STP mean on these sheets, Tala?

   • Standard temperature and pressure: 25 °C and 1 atm
   • Standard temperature and pressure: 0 °C and 1 atm
   • A steady temperature kept in a sealed pot
9. 9.

   Can you use 22.4 L/mol for a balloon of CO₂ at 25 °C, Zee?

   • No: 22.4 L/mol holds at 0 °C and 1 atm
   • Yes, as long as the gas is CO₂
   • Yes: 22.4 L/mol works at any temperature
10. 10.

    IUPAC's standard uses 0 °C and 100 kPa. What molar volume goes with it, Esme?

    • About 2.27 L/mol
    • 22.4 L/mol, the same as at 1 atm
    • About 22.7 L/mol