Why is it necessary to wait until the filter paper containing a compound is completely dry before weighing it? and how would it effect the theoretical yield? HIgher?? lower??
Think about it. Do you want to know the mass of the ppt + water or do you want to know the mass of the ppt only. If I've interpreted the question properly, the theoretical yield will be be affected but the actual yield will be higher (of course, since you are weighing water).
It is necessary to wait until the filter paper containing a compound is completely dry before weighing it because any moisture present in the paper or the compound can affect the accuracy of the measurement. Moisture can add weight to the compound, leading to an overestimation of its mass. This can introduce errors and affect the validity of experimental results.
When weighing a compound, we are interested in determining its actual mass, which is its dry mass excluding any moisture. By waiting for the filter paper and compound to be completely dry, we ensure that the weight we measure accurately represents the mass of the compound alone.
In terms of the effect on theoretical yield, the drying process primarily affects the measured mass rather than the actual amount of the compound present. The theoretical yield is the maximum amount of product that can be obtained from a given reaction based on stoichiometry. It represents an ideal value calculated using the balanced chemical equation.
Drying the filter paper and compound before weighing does not directly impact the theoretical yield. Theoretical yield calculations are based on the number of moles of reactants and their stoichiometric ratios, not the mass of the filter paper. However, if the measured mass is incorrect due to moisture, it can affect the calculated percent yield, which compares the actual yield obtained in an experiment to the theoretical yield.
In summary, waiting for the filter paper and compound to dry before weighing ensures accurate measurements and prevents any moisture-related errors, but it does not directly affect the theoretical yield.