Windex plus Cockroach = dead roach, what's the chemical reaction that makes it happen?

I think the anatomical level is a bit too large to understand the activity of ammonia in the body; a cellular level is necessary, and perhaps even smaller than that.

I should add that the exact behavior of molecules within the body is difficult to determine and is by no means proven beyond any shadow of a doubt. I think the most important reason that the windex killed the cockroach is because of the ammonia.

Cockroaches breathe through a number of openings on their bodies (i.e. not through their mouth) and it is likely that being sprayed with windex woud have resulted in the ammonia being very quickly absorbed into the cockroaches body where its cells would be in danger.

Once it reaches the cells, the ammonia may have disrupted oxidative phosphorylation, the process by which cellular "energy", in the form of ATP, is produced. Essentially, mitochondria (where oxidative phosphorylation takes place) has 2 membranes around it, and it actively pushes hydrogen ions to the space between these two membranes. A hydrogen ion is just a single proton which has a positive charge, so multiple ions start to repel each other. Imagine trying to hold the two positive ends of a pair of magnets together. It takes effort to kepp them close. Essentially, when a hydrogen ion escapes and crosses to the other side of the membrane, energy is produced and this is used to form ATP.

Ammonia acts as a Lewis base in its reaction with a hydrogen ion; it donates an electron pair. Basically,

NH3 + H ---> NH4

ammonia hydrogen ion ammonium ion

I apologize for being unable to depict the charges and atomic bonds as they move, form, and break, but bear with me.

Anyway, you should see that Ammonia picks up hydrogen ions. So once ammonia gets inside a cell, it has the ability to collect the hydrogen ions that were supposed to be used for oxidative phosphorylation. Since oxidative phosphorylation is no longer occurring, the cells cannot produce energy and will die, quickly followed by the death of the organism.

This is just one theory, however. You said yourself that there are other chemicals in Windex, some of which may be more important in the cause of death. Similarly, you may have just cut off its air supply by covering it with windex. There are lots of different ways the cockroach may have died given the circumstances, and I simply do not have the experience whether or not my way was the "most important" one or not.

Chemicals In Windex

There is nothing in your examples that would suggest that "love" or any type or it is not a chemical reaction. You have thought of "valid" examples of "love" and essentially claim that they can not be "chemical reactions" in your brain, but you have not actually looked to see what goes on in the brain when these emotions occur. We do know that both "lust" and "infatuation" (or the early stages of "love") are caused by different sets of chemical. Basically you are arguing from incredulity ("It doesn't sound right to me, so it must be false") rather than from any factual knowledge.

I think the chemical reaction would be "death by old age."

... nothing in Windex would have killed a roach that quickly