- Immediate grading - if you want student entries to be graded during lab as they enter their lab practical results, then the Lab Practical should be constructed as a typical interactive lab report webpage.
- Delayed grading - users that want the Lab Practical to be graded "after the lab" will structure the Chem21Labs webpage so that students submit calculations as "data" . . . . where the "data" is simply "accepted." At a later time, the calculations are graded via "Web Reports." The grading is still automatic (no extra work for the Instructor), just delayed.
Snow Day Labs
Universities that may have classes cancelled due to weather have used the random number feature in Chem21Labs to "generate" lab data. Two approaches have been used:
- Create a Separate Lab- the "original" lab can be duplicated and the "random data" appears in all the places where lab data is normally entered by the student.
- Hide the random numbers under a "More Information" link - labs that are assigned during weeks where inclement weather is likely are modified so that a "set" of random data is generated for each student. This data is "hidden" under a "More Information" link . . . . click the link below to learn more.
If your lab was cancelled, your lab instructor is authorizing the use of the lab data below. This data is unique to you, do not use another student's data. Enter the data below exactly as shown as the lab data for this lab.
Mass of KHP . . . . 0.1206 g
Initial volume of strong acid . . . . 5.01 mL
Volume of water added to cover the pH probe . . . . 67.71 mL
Initial pH (strong acid) . . . . 2.06
Initial volume of acetic acid . . . . 5.03 mL
Volume of water added to cover the pH probe . . . . 63.30 mL
Initial pH (weak acid) . . . . 3.33
A Lab Final can be constructed as a combination of the Lab Practical and the Snow Day lab. In addition to the features mentioned above, some universities prefer to have an "out of class, timed" Lab Final. When a student clicks on a timed Chem21Labs assignment, an alert box appears that informs the student that the assignment is timed and that as soon as they click the "OK" button, the timer will start.