Final answer:
The question involves calculating the mass% of ZnS lost during washing in a specific solution by using solubility product constants and equilibrium information. However, to provide an accurate calculation, additional data like the exact Ksp for ZnS is required.
Step-by-step explanation:
The student is asking about the loss of ZnS precipitate when washed with a solution of HCl and H2S. To calculate the mass lost, we must first find the solubility of ZnS in the given washing solution. This involves using Ksp (solubility product constant) and the information provided regarding the solubility equilibrium of ZnS in the presence of H2S and HCl. For an accurate calculation, one would need the exact Ksp value for ZnS, which is not provided here. Assuming quantitative recovery, any loss of precipitate due to solubility would be considered unacceptable because it would affect the purity and yield of the isolated ZnS.
The calculation would be similar to an Example of Percent Yield calculation in chemistry where the initial amount of substance is compared to the amount recovered after a reaction or process. The mention of equation reference numbers suggests this is part of a more extensive problem set or textbook example, which would provide the necessary constants and background information for a complete solution.