Page 2: Yield Calculations and Percent Yield
Understanding Yield in Chemical Reactions
This page focuses on the concepts of theoretical yield, actual yield, and percent yield in chemical reactions. These concepts are crucial for understanding the efficiency and practicality of chemical processes.
Definition: Theoretical yield is the amount of product predicted by stoichiometry through calculations.
Definition: Actual yield is the actual amount of product made during a real reaction.
Highlight: The theoretical yield will always be larger than the actual yield.
Percent Yield Calculations
The guide introduces the concept of percent yield and provides examples of its calculation.
Definition: Percent yield is the ratio of the actual yield to the theoretical yield, expressed as a percentage. It represents the efficiency of the reaction.
Highlight: Percent yield should never be above 100%.
Examples of Yield Calculations
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Calcium Carbonate Decomposition:
CaCO₃ → CaO + CO₂
- Given: 24.8g of calcium carbonate heated
- Theoretical yield of CaO: 13.90g
- Actual yield: 13.1g
- Percent yield: (13.1g / 13.90g) × 100 = 94.2%
-
Copper(II) Nitrate Decomposition:
2Cu(NO₃)₂ → 2CuO + 4NO₂ + O₂
- Given: 15.0g of Cu(NO₃)₂
- Calculation of theoretical yield of O₂: 0.2 mol O₂
-
Calcium Hydroxide and Hydrochloric Acid Reaction:
Ca(OH)₂ + 2HCl → CaCl₂ + 2H₂O
- Given: 65.0g Ca(OH)₂
- Theoretical yield of CaCl₂: 97.35g
These examples demonstrate how to calculate theoretical yield and percent yield in various chemical reactions, illustrating the practical application of stoichiometric principles.
Example: In the calcium carbonate decomposition reaction, the percent yield is calculated as (Actual Yield / Theoretical Yield) × 100 = (13.1g / 13.90g) × 100 = 94.2%.
This comprehensive guide provides a solid foundation for understanding and applying stoichiometric calculations in chemical reactions, from basic mole ratios to complex yield determinations.
