Not chemicals, beer.
I'm not kidding.
At least he got away from the brewery for the Warp Core itself. The outside had obvious waveguides and looks like part of the fusion research projects. I saw lawrence livermore labs credited too.
As for the film it is better than the last one. However Kirk still displays almost no brains or ability other than dumb luck. The best bit of character development in the whole film was him trying to spare the crew. The whole film was lacking in tactics and signs of intelligence in the characters. Wrath of Khan was clever because both Khan and Kirk were thinking about their next moves and clearly planning ahead. We had one instance of that in the whole film with Harrison. Also the shields seemed to be completely tissue paper..
Things he got wrong included still way too much lens flare - for fecks sake he had street lights doing it. The Enterprise now apparently can enter an atmosphere and the sea (which she was never designed for) without ill-effect. (Aside from Scotty kvetching.) The Klingon Neutral zone is within easy visual range of Qo'nos and Praxis - which makes no sense astronomically speaking. Also apparently Praxis has blown early in this universe. Geology isn't making much sense either as having a cliff with deep enough water directly off it to hide a twenty story starship in. Speaking of design goofs - who puts a massive light well with crossing bridges in the middle of a starship? I get they don't feel cramped for space but having such a massive air volume that servers no purpose other than looking cool and giving you a massive volume that damage can breach and suck air out of. Sensible for a cruise ship, maybe. But an exploration vessel that might have to take combat? Not so much.
That also is the thing that makes little sense. So much waste space within the ship. It takes energy to lug the ship around so all these big airy rooms that have dead space in them make little sense. Hell even the 'cramped' Dreadnaught had huge rooms in to let them slip n'slide around in. Scale of the universe was way off with how fast warp moves you around too.
Add on spectacularly unsubtle foreshadowing with both the kid and the tribble, characters who don't seem to show much intelligence (Kirk gets two moments at Starfleet headquarters with the query about the point of the London explosion and how he downs the attack hopper, Spock gets one.)
There was the potential for a classic in here. If they had expanded the maneuvering between Kirk and Harrison and also expanded the base theme of what StarFleet's purpose is (like, y'know, some diplomacy actually working) this could have been really good. Instead it is a pop-corn action film which is fun but lacking...