Lab 10: Mole-Mass Relationships Lab

Purpose
The purpose of this lab is to establish the relationships between moles and mass within chemical formulas by asking students to predict the quantities of chemical reactions and to identify limiting factors in the reaction. This lab allows students to gain deeper insight into the mass-mole relationship and also helps students to further hone their mole-mass conversion skills. Students were asked to compare their theoretical yield with the actual yield after the lab as well.

Lab Manual #1-4

Possible Sources of Error in Percent Yield 
 Our percent yield ended up being greater than 100%. We believe that this may have been due to an overabundance of hydrochloric acid in the reaction. While we were applying the acid we added several drops even after it had stopped sizzling just in case it had not completely finished reacting, but this appears to have increased the mass of our final product. Even though some of the product was burned from sitting on  the ht plate for too long, the final mass was still higher than the theoretical yield. In addition, our assumption is supported by the deeper shade of yellow our final product had, especially when we compared it to the products of other partners. We believe that this deeper shade of yellow is due to too much HCl.

Our final product. A shown by the photo, it ended up being somewhat burnt; we believe that this may have had some impact on our final calculations.