Respuesta :
Explanation:
4. To find the percent yield of the precipitation reaction, we need to compare the actual yield of calcium carbonate obtained with the theoretical yield we would expect based on the balanced chemical equation.
First, let's calculate the moles of calcium carbonate obtained:
Molar mass of CaCO₂ = 40.08 g/mol + 12.01 g/mol + (16.00 g/mol × 2) = 100.08 g/mol
Number of moles of CaCO₂ = Mass / Molar mass = 0.650 g / 100.08 g/mol
Next, let's calculate the moles of calcium chloride (CaCl₂) and sodium carbonate (Na₂CO₃) used in the reaction:
Moles of CaCl₂ = Volume × Concentration = 100.0 mL × 0.100 mol/L / 1000 mL/L = 0.0100 mol
Moles of Na₂CO₃ = Volume × Concentration = 100.0 mL × 0.200 mol/L / 1000 mL/L = 0.0200 mol
Since the stoichiometry of the balanced equation is 1:1 for CaCl₂ and Na₂CO₃ to CaCO₂, the limiting reactant is CaCl₂.
Theoretical yield of CaCO₂ = Moles of limiting reactant × molar ratio of CaCO₂ to limiting reactant × molar mass of CaCO₂
= 0.0100 mol CaCl₂ × (1 mol CaCO₂ / 1 mol CaCl₂) × 100.08 g/mol
= 1.0008 g
Percent yield = (Actual yield / Theoretical yield) × 100
= (0.650 g / 1.0008 g) × 100
= 65.00%
Therefore, the percent yield of the precipitation reaction is 65.00%.
5. To find the percent yield of the fermentation reaction, we need to compare the actual yield of ethanol obtained with the theoretical yield we would expect based on the balanced chemical equation.
First, let's calculate the mass of ethanol obtained in the fermentation:
Mass of ethanol = Volume × Density = 10,000 L × 0.79 kg/L = 7,900 kg
Percent yield = (Actual yield / Theoretical yield) × 100
= (7,900 kg / 18,420 kg) × 100
= 42.86%
Therefore, the percent yield of the fermentation reaction is 42.86%.