These are four electronic OWL-Tutor modules designed  to reinforce the aspects of  Stoichiometry that have been covered in the laboratory.  They are similar too, but SEPARATE from the Owl  lecture assignments.  The deadlines for completion of these Lab-OWL will be announced in lab.  In general you  have seven days to complete the module once it has been assigned.  The deadline announcements will also appear on the main Chem 121 web page.