Students combine sodium carbonate and hydrochloric acid generating carbon dioxide gas which is allowed to escape. They measure the actual yield of carbon dioxide produced (missing mass), calculate the theoretical yield using stoichiometry, and then the percent yield. Students understand that 100% yield is the most appropriate answer (based on the Law of Conservation of Mass), so after considering the meaning of significant figures and the uncertainty of their measurements they are asked to decide if they did (or did not) get an answer that might indicate the validity of the Law.
This laboratory exercise accompanies the article "A guided group inquiry lesson on coordination compounds and complex ions". The laboratory serves as part of an extended exercise on the chemistry topic of coordination compounds and complex ions. The entire lesson as described in the article also exposes students to how chemical research is conducted and the conflicts and uncertainties that lead to new theories and discoveries.
I expect that most high school chemistry teachers assign some type of laboratory related to types of chemical reactions including synthesis, decomposition, single replacement and double replacement reactions. I have used several published versions, but I am sharing my modifications.
This is a series of experiments, PhET Interactive Simulation activities, and clicker questions to relate macroscopic and molecular representations of homogenenous solutions. Graphing skills are also used.