Full Metal Alchemist brotherhood draws inspiration from the real world practice of alchemy, so what is alchemy and how true to science is flame alchemy. Alchemy is a combination of philosophy and early scientific knowledge and practices. This particular pseudoscience had many aims, including creating an elixir of immortality and turning lead into gold. While it was thoroughly steeped in mythology, alchemy did help to give birth to modern chemistry through the systematic approach used by many alchemists. This led to the discovery of a variety of elements and other chemicals including Aqua Regia and Aqua Fortis.
Aqua Regia is a 1 to 3 molar ratio of Nitric and Hydrochloric acid, which can dissolve gold and platinum.
Aqua Fortis is Nitric Acid- HNO3
However, things work a bit differently in Full Metal Alchemist (I am referring to the Manga and the second anime series brotherhood). Alchemy retains its mix of philosophy and pseudoscience, but here it actually works within a set of principles. The most important of these is the law of equivalent exchange. This is a fancy way of referring to the Law of Conservation of Matter. This real world law of chemistry states that we cannot create or destroy matter; it can, however, be changed from one form to another. What this all means is that you can’t get something for nothing, a strong recurring theme of Full Metal Alchemist. You’ll notice that I left out the Law of Conservation of Energy because A, spoilers, and B, that’s a lesson for another day.
Now that we have the basics done, we can take a closer look at the signature alchemy of everyone’s favorite Colonel. Yes, I am talking about Colonel Roy Mustang’s flame alchemy. Leaving the energy that drives his alchemy out of it, we will be looking at the actual chemistry he is using when trying to blow Edward Elric into next week. The basis of flame alchemy comes from the manipulation of the compounds present in the air in order to create a flame using a spark from Mustang’s signature gloves. A flame can be the result of many different reactions, and we need to take a closer look at the types of flames created by Colonel Mustang before we can break down the chemistry involved.
As you can see there are two basic attacks: an explosion of various sizes, and a flame of various sizes. If you remember equivalent exchange or the law of conservation of matter, then we know that the chemicals that he used to make those attacks must be able to be made from elements present in the air.
We will assume that the atmosphere of Amestris is similar to Earth’s. Thus Earth’s atmosphere is around 21% oxygen, 0.04% carbon dioxide, 0.0002% methane and .001 to .005% water depending on the local atmospheric conditions. There are other elements and compounds but they cannot be used in flammable reactions and some of them can be used to put out fires.
The source material states that Colonel Mustang uses his flame alchemy to break down water to create hydrogen gas. The hydrogen can then be mixed with oxygen and ignited to create a powerful explosion. As you will see below igniting hydrogen and oxygen will create a powerful explosion and liquid hydrogen and oxygen were used to fuel the space shuttle. The exact reaction is shown below.
Step 1- Electrolysis
2H2O --> 2H2 + O2
Step 2- hydrogen and oxygen explosion
2H2 + O2 --> 2H2O
Real Life example
In conclusion, Full Metal Alchemist gets the chemistry of the large explosion correct and when you include the magic bit to make the alchemy work I can call it
Colonel Mustang’s classic flame thrower, however, is a bit of a different story. The previous trick won’t quite work here as he is more likely to blow himself up in a massive explosion if he tries to generate a continuous or controlled flame using the hydrogen and oxygen trick. Hydrogen gas is highly flammable and can auto-ignite when mixed with the right amount of oxygen. This is great when you want to blow something up, not so much if you want any degree of control. So sadly the previous explanation will not work here, which is what the source material uses, so I have to call it
So how would the flame alchemy flame thrower actually work in the universe? Well, the composition of the atmosphere gives us the answer. Methane is a small component of the atmosphere, and it just so happens it is highly flammable, just not as much as hydrogen. Our atmosphere is only 0.0002% methane and much of that has been released more recently. This is due to industrial farming, large scale sewage treatment, and natural gas mining. All are things that the world of Amestris is doing, given the level of technology seen in the manga/ anime. Thus, Colonel Mustang is going to have to make his own source of methane using his alchemy. He can do this by first breaking down water into hydrogen and oxygen like with his explosions. He then will combine the carbon dioxide and hydrogen to make methane and oxygen. The methane can then be burned with the oxygen to create the signature flame attack. The full reactions are shown below.
2H2O --> 2H2 + O2
CO2 + 2H2 --> CH4 + O2
CH4 + 2O2 --> CO2 + 2H2O
The colonel is not limited to just methane however, he could use the same method to make other gaseous hydrocarbons such at ethane, propane, or acetylene. By using different fuels can modulate the properties of the flames giving him a wider variety of uses. One such example would be using acetylene to cut through steel. If you have comments or questions please leave them in the comments section below.