Final answer:
The theoretical true mass % for copper in copper sulfate pentahydrate is determined through stoichiometric calculations based on the molecular formula, resulting in a fixed ratio of elements within the compound. The mass percent of copper is calculated by dividing the atomic weight of copper by the molecular weight of the compound and then multiplying by 100%.
Step-by-step explanation:
The theoretical true mass % for copper in copper sulfate pentahydrate can be determined through stoichiometric calculations. These calculations are based on the compound's molecular formula, CuSO4•5H2O, which implies a fixed ratio between copper, sulfate, and water molecules.
For copper sulfate pentahydrate, the molecular weight is calculated by summing the atomic weights of all atoms in the formula. The molecular weight of copper sulfate pentahydrate is 249.68 g/mol. Copper's atomic weight is 63.55 g/mol. To find the mass percent of copper in the compound:
Calculate the mass percent of copper (Cu) by dividing the atomic weight of copper by the molecular weight of the compound and then multiply by 100%.
Mass % of Cu = (63.55 g/mol / 249.68 g/mol) * 100% = 25.45%
This percentage represents the theoretical true mass % of copper in the compound, assuming that there are no impurities or compositional variations.