Question

In a reaction, 10.76 g of CaCO₃, 10.51 g of HCl, and excess water produced 10.26 g of CaCl2·6H₂O. Calculate the theoretical yield of calcium hexahydrate.

Answer 1

The theoretical yield of calcium hexahydrate (CaCl2·6H₂O) is 16.51 g. This calculation is based on the stoichiometry of the balanced chemical equation, where CaCO₃ is the limiting reactant. The actual yield of 10.26 g yields an efficiency of approximately 62.2%.

Step-by-step explanation:

In this reaction, involving calcium carbonate (CaCO₃) and hydrochloric acid (HCl) with excess water, the goal is to determine the theoretical yield of calcium hexahydrate (CaCl₂·6H₂O) formed. The reaction can be represented as:

`\[ \text{CaCO₃ + 2HCl} \rightarrow \text{CaCl₂·6H₂O + CO₂} \]`

The molar masses of CaCO₃ and HCl are used to convert the given masses (10.76 g and 10.51 g, respectively) into moles. The stoichiometry of the balanced equation indicates a 1:2 ratio between CaCO₃ and HCl, revealing that CaCO₃ is the limiting reactant. From the moles of CaCO₃, the theoretical yield of CaCl₂·6H₂O is calculated using its molar mass. The actual yield is reported as 10.26 g, and by comparing this to the theoretical yield of 16.51 g, we find an efficiency of approximately 62.2%. This efficiency value indicates the proportion of the theoretically possible product that was obtained under the given conditions.

It suggests that not all the CaCO₃ reacted to form the expected amount of CaCl₂·6H₂O, possibly due to factors like incomplete reaction, side reactions, or experimental errors. Understanding stoichiometry and theoretical yield is crucial in chemistry as it provides insights into the quantitative aspects of reactions, helping predict and analyze the outcomes in a systematic and precise manner.