Hello,
I just finished an experiment in class dealing with the separation of a sand and salt mixture through the means of filtration (with filter paper and water) and evaporation (using a hotplate). As I was calculating the percent recovery, I yielded 103.93% of the recovered mixture. In comparing my measured sample before filtering to my recovered mixture, I also had an extra 0.10 g. Do you have an answer as to why I may have a percent recovery over 100%?
Also, is it possible for there to be minuscule amounts of left over water from evaporating the water from the salt (like 0.10 g for example)? Like could there be impurities from the water that I may have failed to fully dry off? In addition, my filtered paper with the sand, and the flask that evaporated the water from salt had a chance, for these last four days, to evaporate more, so would the water be completely dried off by now, or there is still water that has not been evaporated? Finally, could external contaminants have altered the mass and made the mass of the recovered mixture more than what it originally weighed?
I can not conceive a thorough idea on what else I could have done wrong and I would like to have an extra opinion on my experimental uncertainty.
Thank You!