Grade 10 Chemistry practice

What is on the worksheet

1. A 258 g sample is 76% desired substance by mass. Find the desired substance mass. Round to 3 decimal places if needed. Answer in g.

2. For the abstract reaction A + 2B → C, 25 mol A and 45 mol B are available. Assume complete consumption of the limiting reactant. Find the maximum amount of C. Round to 3 decimal places if needed. Answer in mol.

3. For A ⇌ B, use Kc = [B]/[A]. Equilibrium concentrations are [A] = 0.3 and [B] = 0.2 mol/L. Find Kc. Round to 3 decimal places if needed.

4. A hydrocarbon molecule contains 8 carbon atoms. In a complete-combustion model, all its carbon forms CO₂. How many moles of CO₂ come from 6.6 mol hydrocarbon? Round to 3 decimal places if needed. Answer in mol.

5. A model sample has mass 184 g and stated molar mass 14 g/mol. Find its amount. Round to 3 decimal places if needed. Answer in mol.

6. A 247 g sample is 90% desired substance by mass. Find the desired substance mass. Round to 3 decimal places if needed. Answer in g.

7. A 13 mL aliquot at 1.1 mol/L is diluted to 143 mL total without reaction or loss. Find the final concentration. Round to 3 decimal places if needed. Answer in mol/L.

8. Use PV = nRT and R = 8.314 kPa·L/(mol·K). Find the ideal-gas volume for 0.4 mol at 371 K and 144 kPa. Round to 3 decimal places if needed. Answer in L.

9. For one reaction as written, a bond model requires 793 kJ/mol to break bonds and releases 699 kJ/mol on forming bonds. Estimate ΔH. Round to 3 decimal places if needed. Answer in kJ/mol.

10. For one reaction as written, a bond model requires 602 kJ/mol to break bonds and releases 691 kJ/mol on forming bonds. Estimate ΔH. Round to 3 decimal places if needed. Answer in kJ/mol.

11. A sample contains 1.1 mol and has stated molar mass 68 g/mol. Find its mass. Round to 3 decimal places if needed. Answer in g.

12. A supplied valid-range calibration is S = 4c + 0.5. The signal is 3.6. Find c in the calibration's arbitrary concentration units. Round to 3 decimal places if needed.

13. A hydrocarbon molecule contains 1 carbon atoms. In a complete-combustion model, all its carbon forms CO₂. How many moles of CO₂ come from 5.1 mol hydrocarbon? Round to 3 decimal places if needed. Answer in mol.

14. A model solution contains 1.9 mol in a final volume of 1.59 L. Find its molar concentration. Round to 3 decimal places if needed. Answer in mol/L.

15. A model solution contains 0.2 mol in a final volume of 1.03 L. Find its molar concentration. Round to 3 decimal places if needed. Answer in mol/L.

16. A model sample has mass 235 g and stated molar mass 70 g/mol. Find its amount. Round to 3 decimal places if needed. Answer in mol.

17. Measured from the same origin, a spot travels 63 mm and the solvent front 70 mm. Find Rf. Round to 3 decimal places if needed.

18. A reactant concentration decreases from 0.63 to 0.42 mol/L in 56 s. Find its positive average disappearance rate. Round to 3 decimal places if needed. Answer in mol/(L·s).

19. Measured from the same origin, a spot travels 82 mm and the solvent front 113 mm. Find Rf. Round to 3 decimal places if needed.

20. An aqueous solution has concentration 0.4 mol/L. A model aliquot has volume 240 mL. Find the solute amount. Round to 3 decimal places if needed. Answer in mol.