Chemistry Can Do Anything

It's amazing what you can do with a few chemicals in a science fiction story. Mix a bit of Phlebotinum salt with a dash of Suspension of Disbelief, heat it to over 9000 degrees and you have yourself a "chemical substance" capable of whatever you want it to do. A character can down a shot of it, inject it into his/her body, pour it into a machine. In almost no circumstance will it make them throw up, kill them, or ruin the machine. Instead it will create whatever wondrous or horrible effect the author desires.

See also: Lightning Can Do Anything and I Love Nuclear Power. It is of course a form of Applied Phlebotinum. Sci Fi Counterpart of Alchemy.

Anime and Manga

 * 8 Man recharged his cyborg body with "special cigarettes" laced with radium.

Comic Books

 * The original Flash got his powers from fumes given off by "hard water" spilled in a chemistry lab.
 * Captain America gets his powers from a "super soldier formula".
 * Doctor Midnight got his powers from an ill-defined combination of vitamins and ... stuff called "Miraclo".

Film

 * In the failed pilot TV movie Exo-Man from 1977, a scientist is attempting to create an ill-defined compound or alloy that will do something equally ill-defined but apparently magical with ultraviolet energy. The research process consists of the scientist and his assistants mixing up batches of stuff and testing them, over and over again. Naturally, the only sample that works is the one that gets whipped up by one of the assistants just goofing around and tossing random junk into the mix -- right before he is killed by mob hitmen in the same attack that paralyzes the scientist. The scientist doesn't think to analyze the working sample to figure out what it is and reproduce it, thus achieving his original research goals.  Instead he builds a suit of power armor using the few bits of the stuff he has, and goes out fighting crime in it.

Literature

 * A classic example is the potion from Dr. Jekyll and Mr. Hyde that causes the transformation.
 * In Herbert West Re-Animator, bringing fresh corpses back to life merely requires the injection of the right chemicals. Apparently these chemicals diffuse very quickly since they'd be injected into a body with no blood circulating.
 * ''The Invisible Man: The title character's invisibility is chemical in nature.
 * In an interesting invocation of the trope, E. E. "Doc" Smith's The Skylark of Space (one of the earliest Space Operas) begins with the discovery of a transuranic element which catalyses a direct matter-to-energy conversion, with the energy emerging as a form of propulsion (as well as several other useful forms).
 * Isaac Asimov wrote a series of articles about the endochronic properties of resublimated thiotimoline, a substance that dissolves in water before the water is added.
 * In one of Norman Hunter's "Professor Branestawm" stories, a formula that could bring pictures to life came in contact with some old photos, resulting in multiple copies of himself, Colonel Dedshott and Mrs. Flittersnoop and, in a particularly comic case, a half-policeman who was in one shot by mistake. (He kept hopping around the house saying "Pass along p-", which was all he could manage of what the real policeman had been saying when he was caught on film.)

Live Action TV

 * In Family Matters, Urkel creates a machine that can create clones or turn people into other people (e.g., Steve Urkel into Stephan). It required vaguely described "chemicals" to work, which were poured into a slot in the machine.

Video Games

 * In Final Fantasy V, the Chemist class is considered a Game Breaker by experts because of its variety of powers: HP Drain, loads of status buffs, debuffs, and plenty of tools that make the game a walk in the park. They're a Guide Dang It though, as the game doesn't tell you the ingredients for their Mixes.
 * Mixing returns in the Final Fantasy X series and is just as strong, and is the key to many Self Imposed Challenges.
 * Creatures, a complex life simulator, uses "chemicals" for monitoring most of the Creature's inner workings - metabolism, antigens and antibodies, drives like hunger and adopting a right kind of gait for each type of terrain. In some installments of the game, the player can directly inject any of these chemicals in their Creatures, allowing almost anything from clinical immortality to horrible, painful death.
 * Escape From St. Mary's: The chemistry department brews teleportation mixtures from chemicals that you find and distill.

Web Comics

 * Shows up often in Axe Cop. This being Axe Cop, it's often taken beyond the impossible.

Western Animation

 * Chemical X in The Powerpuff Girls.
 * In American Dragon: Jake Long, Spud goes to a school for child geniuses. In a chemistry demonstration one makes a floating cloud in the shape of Pi and another manages to rapidly grow a statue of the teacher.
 * Transformers Generation 1 episode The (aptly named) Insecticon Syndrome had Ratchet and Wheeljack formulate an antidote to the Nova Power Core that was about to explode in the Insecticons' stomachs, to stop them from blowing up and destroying most of the Earth.
 * Roger Ramjet's "proton pills".