The purpose for this project is to evaluate a qualitative analysis experiment of the general chemistry laboratory course, CHEM 111, in order to determine the extent of student success and to improve this experiment, for future cohorts of students. Qualitative analysis is the identification of unknown elements in a sample through a series of tests and is an important part in general chemistry education, it also aids in developing students critical thinking ability. In this experiment, an unknown solution of anions is identified through a series of chemical tests executed in a particular order via a student-generated qualitative analysis (“qual”) scheme. The “qual” scheme is created by the CHEM 111 student using their interpretation of observations obtained through chemical tests on single-anion solutions of known identity. Historically, there has been a sense among the CHEM 111 faculty that students have difficulty designing and understanding the role of the “qual” scheme in the analysis of the unknown. Furthermore, anecdotal evidence has suggested the nitrate anion (NO3-) is incorrectly identified substantially more often than the other anions used in this experiment. Survey data gathered from CHEM 111 students in Spring 2016, Fall 2016, and Spring 2017 does indeed indicate that many students encountered problems creating a “qual” scheme, and the anion most often incorrectly identified was NO3-. The survey results suggest the test for NO3- either needs to be explained more clearly to the students or substantially altered to reduce barriers to its success. A few chemical alterations of this test will be presented, as will information about how modification of the “qual” scheme can impact students’ success in identifying their unknowns.
