Mechanism Topology evaluator to grade chemistry answers

Updated 30 Aug 2024

Use the Mechanism Topology answer evaluator (expressionOchemEvalMechTopology) to check the order of the boxes in the student’s response and how they're connected by arrows in a mechanism question.

Select Grade as Correct or Grade as Incorrect, then enter the conditions you want to be checked in student answers.
Choose is or is not for the condition "If the topology of the response mechanism ...":
Select linear, cyclic (chain or catalytic), or linear or cyclic (chain or catalytic).
- A linear mechanism has boxes connected by arrows in sequence.
  There is one starting step which only contains an arrow leading from it and one ending step which only contains an arrow leading to it. All other steps have one arrow pointing to them and one arrow pointing away.
- A cyclic mechanism has some boxes which contain more than one arrow leading to them, also known as a loop. It's also possible to have a reaction arrow which originates at the mid-point of another reaction arrow and points to a box. For example, a radical reaction may have a cyclic topology.