This seems like an exercise in using “on” and “in” like a native speaker. Here’s how I would write the two examples (that is, here is a minimal change that makes them sound much better to me):
- I am not sure how well I did
in on the test at school today, but I think I might pass.
On In making the coffee, the stove got burned.
This mention of a test takes a common form, where the abstract noun referring to an evaluation is essentially reduced to the paper (or screen) on which the test is written. That’s my fancy explanation for the fact that “did well in the test” sounds odd for a person to say about themselves. “Salt did well in the test” sounds normal, however, probably because that’s an experiment and salt is inanimate.
In the second example, I believe your instincts are correct. What you might not know is that “in” can mean “while” or “in the process of”. I don’t think anyone would be too confused to hear it in its original format (other than wondering how Sarah is to be pitied for the stove being burned). After all, “on” can also mean “upon” as in “at the moment (of making coffee)” which only sounds slightly strange, probably to do with the fact that making coffee is a continuous process (not instantaneous).