• Submitting Lab Data
• Submitting Calculations
• Submitting Essays
• Uploading Images
• LewisDraw
• Chem21Draw
• Balancing Equations
• Graphing Lab Data
• Non-Linear Relationships
• Linear Relationships
• Other Problem Types
• PostLab Problems
• Student Resources

• Digital Labs
• Testimonials
• Royalties
• Embedding Content
  • Images, Videos, Webpages, Animations
• Interactive Spectra
• Grading Essays / Images
• Web Reports - Auto-grade Lab Results
• Lab Practical / Snow Day / Lab Final
• Cheating

• Scientific Method
• Heat Capacity of a Styrofoam Calorimeter
• Colligative Properties

• Avogadro's Number
• Ordering Procedure Steps
• Graded Flowchart
• Dimensional Analysis Map
• Random Numbers as Sample Data
• Reading A Buret
• Thin-Layer Chromatography
• pH Calculator
• Water Density Calculator
• Water Vapor Pressure Calculator
• Limiting Reagents
• Activity Series
• Phase Diagrams
• Properties of Solutions
• Qualitative Analysis
• Organic Mechanisms
• Refractometer
• Stereochemistry
• Polarimeter

Submitting Lab Data

Chem21Labs works with the lab coordinator to convert YOUR lab report into an interactive, auto-graded webpage where students receive immediate feedback and multiple attempts. The student lab data (mass, volume, temperature, pressure, concentration, pH, time and absorbance readings) is entered according to the lab instructor's preference as follows. . . .

1. all lab data is entered at the top of the lab report and "redisplayed" throughout the lab report as needed so students do not have to scroll to the top of the webpage to see their data. This appoach is used when students enter their data as it is collected during lab. The lab instructor can quickly "see" the progress of the class by clicking a "lab data report" link.
2. lab data is entered at various stages during lab submission, usually in the order it was collected in lab, but interspersed with calculations, essays, and balanced equations.

The image to the right shows "grouped" lab data entered at the top of the lab report.
Note the following . . . .

a. the lab guide (webpage or pdf) is readily accessible to the student from the link at the top of the webpage.
b. incorrectly entered lab data is easily modified without requiring the attention (or time) of the Instructor / TA. A link on the instructor side displays a list of students that reset their lab data in case further investigation is needed.
c. navigational instructions help students on the first few labs.
d. the Submit Data button (right side panel) saves the lab data to the database.
e. lab data can be "checked" against expected ranges to prevent typos. For example, if the procedure calls for ~ 2 g NaOH the expected range could be set at 1 - 3 g . . . . if the actual mass is 1.987 g and the students accidently enters 19.87 g the expected range code will trigger a message in the Side Panel so the student can fix the issue without having to reset their lab data.
f. lab data can be "checked" against expected decimal places to help students remember to report trailing zeros. For example, if the procedure calls for ~ 2 g NaOH to be weighed on a mg balance, the expected number of decimal places could be set at 3 . . . . if the actual mass is 1.980 g and the students accidently enters 1.98 g the expected decimal place code will trigger a message in the Side Panel.

In both e and f, the message in the Side Panel tells the student to "double-check" the data in question, but they are instructed to  report the data exactly as they recorded it during lab .

A data array (i.e. pooled class data) can be entered by each student, or once for the entire class by the instructor. Then, the program can calculate the MEAN, MIN, MAX, and STDEV of the array and use these values to grade a student's entered value.

For labs that use instruments (pH meter, UV-Vis spectrometer, Temperature probe, etc.) to collect a group of data points, students can copy / paste these x,y values into a rectangular text box where the Chem21Labs program parses and saves the values in the database. The image to the right shows the text box where a student entered pH data collected during the standardization of a NaOH solution.

Then, a graph of the data is displayed on the webpage as a pH curve, absorption spectrum or temperature curve. In the image below, a student's pH data (entered above) is displayed as an interactive graph on the webpage. Clicking the 1^st or 2^nd Derivative button at the top of the graph will re-plot the pH data. In addition, x,y coordinates appear in a tooltip when the student mouses over the graph. Finally, students can draw lines on the graph to help them determine the pH at the equivalence point.