I think the five most important events leading up to the climax are:

1. Archie gives Jerry an assignment to refuse to sell chocolates for 10 days, and then agree to sell on the 11th day.

2. Jerry decides not to ever sell chocolates, and his defiance spreads across the school.

3. At the Vigils' request, Jerry is harassed by getting prank phone calls, the football team refuses to catch Jerry's passes, and Janza beats Jerry up with a few of his friends.

4. The Vigils manipulate the chocolate sale so that all but 50 boxes (belonging to Jerry) are sold.

5. Archie sets up the fight between Janza and Jerry in the school assembly, pretending that the 50 boxes of chocolates will be raffled off.

What are five events after the climax that lead to The Chocolate War's resolution?

If we accept that the climax occurs in Chapter 25 when Jerry stands firm before Archie and the Vigils when he is summoned before them the second time, five events leading from that point to the resolution might be as follows:

1. The Vigils decide to take a leadership role in making "selling chocolates the thing to do" (Chapter 27).

2. The tide of opinion among the students turns against Jerry, beginning with Harold Darcy's challenge to at roll-call in Chapter 30.

3. Jerry is beat up by a gang of kids led by Emile Janza.

4. Archie plans the "raffle" as a final act of humiliation for Jerry, and tricks Jerry into participating in it.

5. Jerry is brutally beaten by Emile Janza before the student body on the field, after which he finally capitulates, deciding it is not worth it to "disturb the universe" (Chapter 38).

What is the climax of The Chocolate War?

I believe the climax occurs in Chapter 25, when Jerry faces Archie and the Vigils after being summoned a second time. He stands firm when questioned about why he has defied their orders and continued in his refusal to participate in the fundraiser, and is given an ultimatum to accept his share of the chocolates at roll-call the next day.