Stoichiometry for gas volume and particle counts

Answer Key - Grade 10 Science Worksheet - Building Confidence

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

1. 1.

   In 2 H₂O₂ → 2 H₂O + O₂, 4 mol of H₂O₂ breaks down. At STP, 1 mol of gas fills 22.4 L. What volume of O₂ forms, Ari?

   44.8 L
2. 2.

   In 2 H₂O₂ → 2 H₂O + O₂, 0.5 mol of H₂O₂ breaks down. At STP, 1 mol of gas fills 22.4 L. What volume of O₂ forms, Bo?

   5.6 L
3. 3.

   In 2 H₂O₂ → 2 H₂O + O₂, 3 mol of H₂O₂ breaks down. At STP, 1 mol of gas fills 22.4 L. What volume of O₂ forms, Esme?

   33.6 L
5. 4.

   Using the map, how do you turn liters of a gas at STP into moles, Jun?

   • Divide by 22.4 L/mol
   • Multiply by 22.4 L/mol
   • Divide by the molar mass
6. 5.

   Using the map, how do you turn moles into a number of particles, Kira?

   Use the picture in question 4.

   • Multiply by 22.4
   • Divide by 6.022 × 10²³
   • Multiply by 6.022 × 10²³
7. 6.

   Using the map, which step links one substance to another, Luz?

   Use the picture in question 4.

   • The mole ratio
   • The molar mass
   • The 22.4 L/mol
8. 7.

   At STP (0 °C and 1 atm), what volume does 1 mol of a gas fill, Milo?

   • 1 L
   • 22.4 L
   • 6.022 L
9. 8.

   What volume do 2 mol of O₂ fill at STP, Pia?

   • 11.2 L
   • 44.8 L
   • 22.4 L
10. 9.

    How many molecules are in 1 mol of water, Ren?

    • 18.02
    • 22.4
    • 6.022 × 10²³
11. 10.

    How many molecules are in 0.5 mol of oxygen gas, Tala?

    • 0.5 × 10²³
    • 3.011 × 10²³
    • 12.044 × 10²³