What IS fire? (and what happened in Beirut?)
Hey. I'm Melissa.
Jam:I'm Jam.
Melissa:And I'm a chemist.
Jam:And I'm not.
Melissa:And welcome to chemistry for your life.
Jam:The podcast helps you understand the chemistry of your everyday life. Hey, Melissa. Guess what?
Melissa:What?
Jam:We forgot to remark on something pretty important in the last episode.
Melissa:What's that?
Jam:It was our 1st episode of the 2nd year of Chemistry For Your Life.
Melissa:Oh my gosh. Really?
Jam:Yeah. We forgot to even remark on it. It was
Melissa:like Oh, yeah. Because we've been we launched on August 1st.
Jam:Yep. That one marks season 2. Not that we really have, like, technical seasons, but Year 2 of chemistry for your life.
Melissa:Wow. That's wild.
Jam:Isn't that weird?
Melissa:That is weird. I can't believe it's been a year of us doing this.
Jam:I know. And it's also weird because I was counting on and it was like, somehow, there were 54 Thursdays in in the past year. Like, I was expecting that we could
Melissa:be started on a Thursday, maybe?
Jam:Right. And August 1st was on a Thursday. So it was like we squeezed as many as we could. Then we got 54 episodes in a year, which seems like it doesn't work out mathematically.
Melissa:That's amazing. Well, that's exciting. It feels New and exciting every time we record stills. So
Jam:Yeah. This seems like there's still plenty of chemistry. Right? Yeah. I
Melissa:don't think we've run out of chemistry yet.
Jam:Okay. Sweet.
Melissa:So that's a good, good segue because the thing I'm bringing up is an old topic that we discussed before.
Jam:Oh, really?
Melissa:And yeah. And I just want you to stop and think for a second and try to answer this question. It came up once before on, I think, our Halloween episode.
Jam:Mhmm.
Melissa:And that question is, what is fire? Just take a moment, however long you need. Listeners at home, you can pause it And try to think. Do you know really what fire is?
Jam:Okay. I've been thinking about it, and I still I'm pretty in awe about what it is and immensely curious just like I was after the Halloween episode.
Melissa:I remember after the Halloween episode, Jim and I have another mutual friend who's a chemist, and we texted him and asked him what fire was. And his initial response was the same as mine, which is it's fire. And then we thought about it a little bit more and realized that we didn't really have a satisfying answer to what fire is. We may also have even gotten this from question from listener Grant. I think he may have been the initial spark.
Melissa:So It's a long reaching question that's been in the minds of us chemistry for your life people. And so I'm gonna say the short answer, fire, the hot stuff that you see, is the result of a chemical reaction.
Jam:That
Melissa:the fire itself, the hot stuff, the the visible hot Area
Jam:Mhmm.
Melissa:Is a release of energy.
Jam:Oh.
Melissa:So a chemical reaction takes place, and there's a very fast Release of energy that's both warm. It's a release of heat energy and light energy.
Jam:That's what the little flames are? Is light and heat, energy being released? Mhmm. This is so weird.
Melissa:There's also some vapors. There's some Water vapor. There's some c o two gas that comes out depending on what's being burned and how completely the Reaction takes place. There's you'll see different things in the flame, but for the most part, what you're seeing is is heat and light. Right.
Melissa:Mhmm.
Jam:I guess that makes sense, but it it feels just, like, So weird to look at if you really think about it. There's these little flames kind of wiggling around. Mhmm. And that's the release of heat and light, which is just Strange.
Melissa:Right? I know. It it feels almost like an anticlimactic answer.
Jam:Right. Or it doesn't totally get the mystery. It's kinda like, well, why does it looked like that. And I
Melissa:think why it looks like that is some of the vapers moving around and stuff. But, yeah, it doesn't I I don't feel satisfied with this answer. And in 2020, someone published an article that I found very satisfying, and it she just kinda talked about how It doesn't feel like we've really solved the mystery of fire yet. Mhmm. And I appreciated that.
Jam:It's like we might know what it is in the most basic of terms, but have we really totally uncovered the mystery of it?
Melissa:Right. I just think the answer to that is not really, which is true for a lot of things.
Jam:Because then it's weird that, obviously, we talked about in that episode how you can turn the fire to be green, And that's still totally fascinating. And then it's like, well that's what I guess happened during that episode. It was like, well, fire is just fascinating on its own. Like Mhmm. The fact that you can change its color is certainly one thing, but it existing at all, if you think about it enough, it's it's like whenever you say a word Too many times, and then it starts to trip you up?
Melissa:Yeah. It says starts to feel unfamiliar in your mouth.
Jam:Yeah. Like, you it too much or you type it too much, and you're like, there's no way pencil is spelled like that. Right? That's not how you spell pencil. Or or the weird pencil just sounds weird to you, and it's like, That's not is that how you say that?
Jam:Why does that it sounds so weird. It's kinda like fire. I mean, that's how I feel. A lot of times in this Show or full exam is something that I've looked at a ton of times, and then it just kind of makes it suddenly Obvious how weird that everyday thing is.
Melissa:Right. Exactly. Oh, and I wanna say I said she, but I believe, actually, the author was a man, Kit Chapman. He's a science journalist and broadcaster, and it was in Chemistry World Magazine, which is the magazine that goes along with the It's the magazine of the Royal Society of Chemistry. We have one of those.
Melissa:The American Chemical Society also has a magazine that goes with it, so it's a pretty trustworthy source. So I appreciated Him capturing the mystery of the of the flame and how it feels like we haven't really got at it yet. Right. Okay. So that's the basics of fire.
Melissa:But generally in chemistry, we say that Fire is a result of a combustion reaction. The very simplest combustion reaction is some kind of fuel with oxygen, and that usually creates carbon dioxide and water. So the simplest fuel would be methanol. That's just, the simplest Carbon surrounded by 4 hydrogens with oxygen. You need some kind of heat to get it to go over the Activation energy or the energy required to start the reaction.
Jam:Uh-huh.
Melissa:And then an exothermic reaction takes place that gives off its own heat and light. It gives off energy. And c o two and h two o are also created. So and can do one of those things where I draw the molecules and show how they rearrange to make the carbon dioxide in the water.
Jam:So that basic fuel, is there Example of that exact fuel in our everyday life. Like, is that an equivalent to some word that we'd we'd recommend?
Melissa:Methane is that fuel. It's a natural gas. So you probably have seen it used in Fuel. Literal fuel. Propane is a more has more carbons.
Melissa:It's made of 3 carbons and has 8 hydrogens around it instead of 1 carbon with 4. And propane gas is the thing that you burn in the tanks in the backyard usually
Jam:Mhmm. Mhmm.
Melissa:For your for your gas grill.
Jam:So the gas in my house is probably methane? I don't
Melissa:know if they use methane or propane for your house gas, but
Jam:but
Melissa:that's it's something like that. It's some kind of hydrocarbon fuel. And then you have oxygen in the air, and you ignite it either with the igniter on your gas stove or with a literal match or lighter, and that gets it that needs that heat to start the reaction. The reaction gives off heat, which allows the next sort of reaction to take place. It's almost like a chain.
Melissa:It fuels itself with the heat released from the reaction.
Jam:Okay.
Melissa:So that's fire. Fire is, In its simplest form, the base best way I know how to describe it is some kind of fuel, something that is capable of burning In the presence of oxygen and there usually needs heat to get it going, and it will let off a lot of energy. It's an exothermic reaction, Let's off energy in the type of, energy is usually heat and light.
Jam:Okay.
Melissa:Okay. And the light comes from the electrons moving around. When electrons are excited, they absorb energy, then they They let off that energy and come back to their nonexcited state, and a lot of times that'll be in the form of light.
Jam:As they're coming back down I think we talked about that in the past.
Melissa:As they're coming back down. Mhmm. In the green
Jam:fire zone. Okay. Yeah. Yeah.
Melissa:So I won't get too much into that, but you can go listen to that episode.
Jam:Dang. That's crazy. There's a lot going on there in that little flame that we use every day, if you have a gas stove, I guess.
Melissa:Or if you light candles every day.
Jam:Right. True?
Melissa:The wax in candles is the fuel.
Jam:Oh. Mhmm. Interesting.
Melissa:And your lighter, is that ignition?
Jam:Mhmm.
Melissa:And then your your beer burning you might also, I guess, be burning the wick. But Right. There's a nice American Chemical Society video, and they talked about the hydrocarbons in the wax being the fuel and the Oxygen in your air combining to keep that flame going.
Jam:Yeah. Interesting.
Melissa:Okay. Now I think We're gonna take that and apply it to a bigger, more relevant situation that's going on now. So before we kinda shift gears, can you give that back to me? Can you explain that back?
Jam:Yes. Okay. So fire is we're seeing the result, basically. It's an ongoing thing, but it's this chemical reaction that's already started, We're seeing it be happening. But before it could even happen, we'd have a fuel, so a Gas of some kind or a, like, I guess, a liquid fuel as well.
Melissa:You can even have wood fuel. There's hydrocarbon in in wood.
Jam:And thing is weird. I wouldn't have thought of them. I obviously, that's, like, when people say adding fuel to the fire, I always just think of You're adding,
Melissa:like, a Lighter fluid?
Jam:Yeah. Right. Right. I don't think of what is fuel, but, obviously, it is. You have to have that And oxygen, which the oxygen thing is interesting.
Jam:I remember, like, as a kid putting a lid on a candle or something on a candle, and it dies out.
Melissa:Mhmm.
Jam:That's interesting. I don't fully understand that. I don't think. But if you have those things present and some ability to raise the The temperature just enough for how do you say that? For the some sort of threshold to be started for the Reaction to begin?
Melissa:Yeah. You kinda have to give it enough energy for the reaction to go, and that's called the activation energy.
Jam:Okay. Right. Because the heat is energy, so it's getting things going. Not just raising the temperature of stuff, but it's also adding energy to the situation.
Melissa:You kick it off. You give it a little jump start there.
Jam:Right. And then the fuel and the oxygen are reacting together.
Melissa:Mhmm.
Jam:And they are, as a result of that reaction, giving off heat and light, specifically the light part being Because the electrons are getting excited, and they're coming back down from that excitement, and they're they're giving off the light as they do that. Mhmm. I mean, the heat is the energy just exothermic It's just
Melissa:another form of energy. So It gives off light as a byproduct of energy and heat as a byproduct of energy.
Jam:And then there are some leftovers of some kind from that. You said water and CO 2?
Melissa:Yes.
Jam:Those are the What would you call those?
Melissa:Those are also products of the reaction. Okay. All of those are products. So we learn about Exothermic and endothermic reactions in general chemistry, so the the 1st or 2nd semester chemistry. And the way that we tend to teach our students is your You'll have your products that are formed as a result of the reaction and your reactants are what you mix together to make the reaction occur.
Melissa:And heat and energy can become a product, or you have to put them in to make it go. In this case, there's an activation energy, so there is some That heat, that kicks it off, but much more heat is given as a product
Jam:Mhmm.
Melissa:Than usually kicks it off. So You can think of the carbon dioxide, the water, and the heat, and the light all as products of this reaction.
Jam:Okay.
Melissa:So they all are result of the combination of oxygen and whatever your fuel is. Now the kind of combustion reaction we're talking about here is if it completely reacts And complete combustion reaction, sometimes it doesn't completely combust, and you can get carbon monoxide as a byproduct from fire. You can get other gases coming depending on what your fuel is. You can have other things going on, but that's pretty, You know, complicated, so I just went with a very basic, you can imagine burning natural gas with Oxygen present with a an ignition point, and that's gonna give you your carbon dioxide and water if it completely reacts.
Jam:Man, I see what you mean about it. Feeling like there's still so much mystery that's not yet solved because it feels like, Okay. I get I have a basic understanding now, but it still seems so weird.
Melissa:It it really is still so weird. And even how to extinguish fire is still being studied. So in that article that talked about the complexity of fire Being hard to grasp still. They talked about trying to find new ways to put out fire besides simply dousing it with water when that's not feasible or could cause more damage.
Jam:Mhmm.
Melissa:And they talked about using sound waves and electricity to put fires out, Which is wild to me. I know. Jeez. And I'm I don't think we could get a ton of information about that. It seemed proprietary because it was At the US Defense agents, their the US Defense Advanced Research Projects Agency is what they're working on.
Melissa:So I don't think he could probably give us a ton of information, but it was really it's really, I think beautiful how complex it is. It kinda reminds me of photosynthesis where we know how it works, but we don't really know everything about how it works.
Jam:Right. Right.
Melissa:Okay. So that's your basic understanding of fire. But the reason I really wanted to do this week is a question I got from, Actually, your wife, Emily.
Jam:Mhmm.
Melissa:She mentioned the explosions in Beirut and how storage of Ammonium Nitrate could have impacted what happened in Beirut. That there's a really tragic explosion that happened this past week a lot of people lost their lives and a lot of people were injured in Beirut. And what scientists who have observed the reaction think happened There's a very large storage of what's known as ammonium nitrate.
Jam:Mhmm.
Melissa:So this chemical reaction of fire is an oxidation reaction, just like we learned about with rust. And you need an oxidizing agent for that. And ammonium nitrate is a very good oxidizer. So there was already a fire burning in Beirut, and It seemed that fire began to heat up a very large, like, several 1,000 ton storage of ammonium nitrate.
Jam:Mhmm.
Melissa:And when ammonium nitrate is exposed to heat, it can break down in a lower temperature to give you one set of products. Or at a higher temperature, Ammonium Nitrate breaks down to form nitrogen gas, oxygen gas, and water. And that Okay. Decomposition in itself is very exothermic. It gives off a lot of energy just by breaking down.
Jam:Mhmm.
Melissa:And we've talked a lot about exothermic reactions. We talked about it in the hand warmers episode. We've touched on it since then, but that just basically means just like with fire, it gives off a lot of energy.
Jam:Mhmm.
Melissa:So that by itself, that decomposition can give off a lot of energy, build up pressure, and if it's stored in a way that there's not a good way to release that pressure, it can be explosive.
Jam:Oh, okay.
Melissa:But as a double whammy, this is my interpretation, so I'm not an explosions expert, obviously.
Jam:Mhmm.
Melissa:It breaks down into nitrogen and oxygen gases. And oxygen gas, as we just Learned is a very key ingredient to fire. So if it's stored improperly with any kind of Fuel. So any kind of paper material, anything that can burn
Jam:Mhmm.
Melissa:Not only will you have this exothermic reaction where it breaks down, but that can the heat and energy that's released in the breaking down of the ammonium nitrate can then ignite a fire if it's stored improperly, Which sort of makes it a double whammy of insanity because you have basically a fireball. If you have a lot of oxygen gas that's been released and stored Next to some kind of fuel Mhmm. That could be paper bags or something like that, and you have the heat from the reaction or heat from an external source, That will ignite it on fire. So you have you almost from what I could tell from studying this reaction, not only is the Rapid decomposition of ammonium nitrate dangerous itself just because it lets off so much energy, but it then is the perfect ingredients for fire if it's stored near something that's combustible.
Jam:Mhmm.
Melissa:So they have to take in double consideration with ammonium nitrate that it needs to be stored in a way that It's not gonna have a lot of it together that builds up pressure to make a really violent eruption. Yeah. And then 2, it needs to be stored away from any kind of fuel and hopefully in a place where it's not gonna have any heat.
Jam:Dang. Wow. That's a lot of Ways it can go wrong.
Melissa:Yes. And ammonium nitrate is actually was has been used in explosives in the past for The Oklahoma City bombing, a government building was bombed in Oklahoma in 1995.
Jam:Mhmm.
Melissa:There's a similar Ammonium nitrate disaster off the coast of Texas with, a ship that had been abandoned with a lot of ammonium nitrate in it. Mhmm. And about a year or 2 ago here in Texas, there's a town called West Texas that had a fertilizer plant that had an a small explosion, and they suspect that ammonium nitrate was also at play there.
Jam:I think that was almost 7 years ago, 6 or 7.
Melissa:Was it?
Jam:Mhmm.
Melissa:Oh, no.
Jam:My friend of mine did a documentary about it.
Melissa:You're right. It was 2013. Wow. Yeah. I'm I'm clearly showing my age that I think that was just a few years ago.
Melissa:Does feel like just a few years
Jam:ago. But yeah. I agree.
Melissa:So ammonium nitrate is well documented to have these properties, and there are a lot of things that can go wrong. Mhmm. It by itself without the external heat or anything like that is fine. It's just A fertilizer that should be perfectly safe, but you just have to be careful in how you store it and what it's exposed to.
Jam:Wow. Dang. That's scary. I did not realize And that was part of the Beirut explosion or that it had a role to play in a lot of other pretty significant explosions, At least a few that we know of, probably even more. Got it.
Melissa:I think I That's crazy. Found something. I didn't check the source on it, but it looked like it was maybe about 30 Ammonium nitrate disasters, on record. So
Jam:Wow. Hikes, dude. That's that's scary.
Melissa:It is scary. And I think it's something about chemistry that, you know, we've started to learn is that they can have these benefits. Ammonium Nitrate is a fertilizer that Allows nitrogen to be used to grow plants. And because we have nitrogen available to us to fertilize the ground with, We're able to make enough crops to support the world population. Mhmm.
Melissa:We needed to learn how to fix nitrogen to do that. You know? So that's really an important thing to keep Our world fed is having nitrogen fertilizers, but this particular one, I don't know if there's others, but then it has a downside of you have to be really careful on how you're what it's getting exposed to. And and, actually, the United States, they do have some regulations already for Ammonium nitrate in uses for explosives, but they're working ever since that happened in West. Mhmm.
Melissa:They're working towards Getting the fertilizer more well regulated so that the fertilizer can't be used for nefarious purposes or for accidents.
Jam:Got it. Got it. Thing is, kinda, gives a whole new side to what we've talked about in the past, the dark side of chemistry.
Melissa:Mhmm.
Jam:This is, like Has a potential to be a very dark side when the wrong things are placed together without the right regulations. Gosh.
Melissa:Right. And that's the importance of having government agencies that regulate that kind of thing is keeping us safe from incidences like these.
Jam:Mhmm.
Melissa:So I just wanted to answer the kind of weird question of what even is fire, but also I wanted to bring some awareness about The importance of chemical regulations and, just to honor some of those victims that are the result of this explosion in Beirut.
Jam:Yeah. I'm really glad we did this topic and and tied it into, obviously, a question that we've had for a long time within something really current and important. We're gonna add some links in our show notes to some information and some ways that you can help the victims of This explosion, one of them is a is an organization I'm really familiar with that's local. I mean, at least they're based local in in Texas, but they have staff Everywhere, and they already have staff on the ground in that are nationals there in Lebanon helping with the situation and trying to help people's needs and and stuff. So if you're interested in any of that stuff, we'll have links to that in the show notes.
Melissa:Awesome. So in light of that tragedy, rather than Spend time talking about the good things that happened in our week. We just wanted to wrap up here and leave the focus on those victims and that tragedy and Have it fresh on your mind to go check out how you can help.
Jam:Thanks, guys. Melissa and I have a lot of ideas for topics of chemistry in everyday life, but we wanna hear from you. If you questions or ideas, you can reach out to us on Gmail, Twitter, Instagram, and Facebook at chem for your life. That's chem, f o r, your life, to share your thoughts and ideas. If you like to help us keep our show going and contribute to cover the cost of making it, go to kodashfi.com slash chem for your life, and donate the cost of a cup of coffee.
Jam:If you are not able to donate, you can still help us by subscribing on your favorite podcast app rating and writing a review on Apple Podcasts. That also helps us to be able to share chemistry with even more people.
Melissa:This episode of chemistry free life was created by Melissa Colini and Jam Robinson. References for this episode can be found in our show notes or on our website. J. R. Robinson is our producer, and we'd like to give a special thanks to s Flint and a Heffner who reviewed this episode.
