Graphing Linear Relationships
Creating and interpreting graphs is a skill that must be included and cultivated in the general chemistry curriculum. As there isn't an expectation that freshmen students possess a working knowledge of Excel, the general chemistry laboratory is the perfect place for students to follow a "guided experience" (described under the More Information link) inside Excel to display their lab data. The Chem21Labs program will display a graph of the student's data as an embedded part of the lab report on the webpage . . . . students can "compare" their Excel graph to this Chem21Labs graph as an initial check that they followed the directions provided by their "guide." Next, the student enters the information they collected during the "tour" . . . . slope, y-intercept, R2, standard deviation . . . . into the Chem21Labs lab report webpage. The student receives immediate feedback on the correctness of their values and either continues with the lab submission process or takes a second "guided tour" through Excel.
In addition to plotting y vs. x , buttons at the top of the graph can be clicked to plot 1/y vs. x , and ln(y) vs. x . . . . these relationships are helpful in understanding PV = nRT relationships as well as whether a reaction follows 1st or 2nd order kinetics.
Additionally, "More Information" (click link below) about graphing lab data with Excel can be delivered to students inside an expandable section - this section can be collapsed using the "Hide Information" link below it.