What is gasoline?
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 helped you understand the chemistry of your everyday life.
Melissa:Okay. So today's episode and the one that we're gonna release in 2 weeks are both inspired by listeners and supporters of the show.
Jam:Nice.
Melissa:One question was from Julian e who supports us on COFI.
Jam:Okay.
Melissa:And the other was by our friend Sam In who supports us by reviewing the episode.
Jam:Mhmm. Mhmm.
Melissa:Okay. So Julian e asked how catalytic converters work.
Jam:Okay. I've heard that term.
Melissa:You've heard the term catalytic converter?
Jam:I know it's important in cars. Mhmm. And that's about it.
Melissa:So it is important in cars, and I went and started looking up some of the information about it. And I could do an episode only about catalytic converters without talking about gas first, but then I thought, did someone ask about how gas worked in cars? And I went back, and Sam Inn had asked how does gas made cars go.
Jam:And how long ago did you do that? Do you remember?
Melissa:I think it was in April, Actually, it was somewhat recently.
Jam:Not too long.
Melissa:Not too long. It was in the height of working on my dissertation. I had to get an episode out, and I had no inspiration, so I reached out to Sam. Yeah. So, so I reached out to Sam.
Melissa:Yeah. So putting those together, I thought goes really well because kinda like converter has do with what happens to the gas after it's done in the car.
Speaker 3:Okay.
Melissa:So I thought it went well as a pair.
Jam:Nice. Nice.
Melissa:So thanks, Julian, and thanks, Sam, for inspiring today's and 2 weeks from now episode. Nice. It's finally here. The answer to that question only, what, 4 months later?
Jam:Uh-huh. Uh-huh.
Melissa:5 months later. And, actually, it reminded me a lot of the episode we had about fireworks.
Jam:Oh, right. Right.
Melissa:So in our episode about fireworks, we talked about how burning gunpowder Gunpowder itself is an explosive.
Jam:Right.
Melissa:But when you burn gunpowder in an confined space, Eventually, the pressure of all the things being released from the chemical reaction overwhelmed the ability of the container to hold That reaction in, and that's when explosion happened.
Jam:Yeah. Yeah.
Melissa:So guess what? What? There's basically a little tiny firework inside your A little tiny explosion happening over and over. Okay. So that's Basically, how gas makes your car go.
Melissa:So inside your car's engine, there's something called a piston.
Jam:Yes.
Melissa:And that piston is inside a cylinder, and it goes up and down. It has the ability to move vertically up and down inside the cylinder.
Jam:Right.
Melissa:But there is a little tiny pocket at the top of the cylinder where the the piston doesn't quite go all the way to the top. Mhmm. So the picture I had in my mind of this is, did you ever have those, like, orange push pop ice cream things?
Jam:Oh, definitely. The Flintstone ones?
Melissa:I don't know if there are 1 set or not. We we
Jam:have 1
Melissa:set once. So imagine that the cylinder is the cardboard tube on the outside Uh-huh. And it's Closed off. There's, like, usually a wrapper or something on the top. Uh-huh.
Melissa:And there's a plastic piece that's sort of pushing the ice cream up, And you can move that up and then back down or down and up and down and up. Even while the lid's still on, sometimes you can get it to wiggle down a little bit Uh-huh. And push it back up. So in your car, the cardboard tube is like the cylinder. The plastic piece is like the piston where it can go up and down.
Melissa:Uh-huh. And then where the ice cream is, that's where air and gas will flow in. Okay. So there's, like, a space at the top that can be condensed down.
Jam:Right.
Melissa:It's smaller than the full ice cream, so it's more like, if you've eaten most of it and then put the lid back on sort of, which why would you do that? But Yeah. That's the visual image. Okay. And also up there is the spark plug for your car is in that part of the top.
Jam:And that spark plug does what it sounds like it does?
Melissa:Yes. So It creates
Jam:a spark?
Melissa:It creates a spark. So and imagine if you will your orange ice cream car. Okay. So at the top where the ice cream goes, between the Lid of the ice cream and the piston. Mhmm.
Melissa:That's where all the ice cream is. Right? Mhmm. So, In your car in that space, air and gasoline are put into there. K.
Melissa:But they are compressed under pressure because the piston is pushed up towards the top.
Jam:Right.
Melissa:So then when it's in that environment, a confined space with oxygen and fuel. Uh-huh. You do a little spark just like when we light our firework. Mhmm. And that spark is enough to start the combustion reaction where the fuel mixes with the air and the energy to create more energy and eventually the air that's, the gas that's being released and the heat that's being put off is all too much to be contained in that space and a sort of explosion happens that pushes the piston down.
Jam:Got it. Okay.
Melissa:So instead of it just exploding All around, you know, like a bomb, it explodes in a more contained way like a firework. Right? It just pushes that Right. That piston down.
Jam:Right. Right. Right. Instead of just, like, exploding out because the piston's ready to move, as soon as something pushes against it Mhmm. It helps relieve the pressure Or harness it, I guess Yeah.
Jam:You could say.
Melissa:It basically takes the energy that's being put out from this reaction and turns it into Working your car. So it pushes the piston down. And when the piston pushes down, it pushes on something else called a crankshaft that moves sort of in a circular motion, And that makes the car literally go.
Jam:Nice.
Melissa:So you so much like a firework.
Jam:Yeah. But a lot Safer, it seems. Safer. Yes. More something.
Melissa:Yes. A lot more controlled maybe.
Jam:Yes. Yes.
Melissa:And in a way that it's harnessing all that energy to put it to work instead of taking all that energy and turning into a light Showing moving on. Yeah. Yeah. Okay. So that's the very basics of how gasoline makes your car go.
Speaker 3:Okay. So
Melissa:that is a chemistry lesson in and of itself. Right? But you've already learned that chemistry lesson on the firework episode.
Jam:Right. Right.
Melissa:So I actually kind of wanted to hone in sort of on the 2nd part of this question. In my mind, almost an implicit question is but then what even is the gas? Ask, like, why is the gas able to burn? Yeah. And something I've wondered a lot is what those numbers at the pump mean.
Melissa:Yeah. So what even is the gasoline?
Jam:Yeah. And I've tried to, like I've mentioned this before we started recording. I recently have looked into this just a little bit. Some science YouTube videos suggested to me. It's still so hard to wrap my head around.
Melissa:Mhmm.
Speaker 3:They weren't
Jam:trying to answer that exact question about, like, the numbers and stuff like that, so I don't really know still. But
Melissa:Right.
Jam:There's just it's funny how something like that that we use every day that is a very, you know, interesting dangerous substance It's super powerful that most of us don't know how it works.
Melissa:Yes.
Jam:Yeah.
Melissa:I I feel like I had no idea how cars worked or how they went Or what gasoline had to do with any of it until I started to research this episode. Yeah. And I will say, though, there was a really good, American Chemical Society video, and we'll put that in our show notes. They're actually talking about hydrogen fuel cells, But they did a quick overview of how cars go with combustion engines.
Jam:Uh-huh.
Melissa:And it was very clear. I really appreciated the The demonstration they did. So you can go check that out if you're still not quite wrapping your mind around how the explosion pushes the piston to turn the wheel.
Speaker 3:Got it.
Melissa:Okay. So but let's talk about what the gas itself is and where it comes from and all of and what those numbers mean and all of that. So the very short answer is that gas is hydrocarbons. Okay. So we've talked about hydrocarbons before, but they are carbon chains, and carbons like to have 4 bonds around them.
Melissa:So there are carbon chains, and Then around the outside, they're sort of filled in with hydrogens to get each carbon up to having 4 bonds around it. So there's carbons connected to each other, and then there's sort of also have hydrogens on each one.
Speaker 3:Okay.
Melissa:So some common hydro hydrocarbons that you've probably heard of are, like, methane. And we've talked about that in a previous episode that methane has 1 carbon and 4 hydrogens around it.
Speaker 3:Right.
Melissa:And then ethane Has 2 carbons, and then because those carbons are bonded to each other, each one only needs 3 hydrogens around it.
Jam:Right.
Melissa:So it's 2 carbons, 6 hydrogens.
Jam:Okay.
Melissa:And then propane, 3 carbons. And because the carbon in the middle has 2 carbons bonded to it on either side, Imagine 3 carbons in a row.
Jam:Right. Right.
Melissa:The first one on the left needs 3. The carbon in the middle only needs 2 hydrogens, and the 1 on the right needs 3 hydrogens.
Speaker 3:Got it. Okay.
Melissa:So these are hydrocarbon.
Jam:Yes. These are kind of I'm able to see sort of see it in my head, which is nice that It has that kind of rule. Like Yes. Carbons want to be bond to as many things. So depending on how many you put, you can kinda do the math.
Melissa:Yes. And there are Hydrocarbons that are known as straight chain hydrocarbons are normal hydrocarbons, and that has all the carbons lined up in a row. So When I described propane to you, it was 1 carbon then another then another.
Jam:Right.
Melissa:But sometimes they're branch.
Jam:Oh, okay.
Melissa:And so sometimes instead of it being the quote, unquote normal hydrocarbon, sometimes it could be, like, shaped more like if you had 4 carbons either all in a row or 3 in a row and 1 bonded off of the 1 in the middle.
Jam:Yeah. Yeah. Okay.
Melissa:Okay. So that's that's a key concept for what we're gonna Talk about with what the gasoline in our car is. So there's normal straight chain hydrocarbons that have all their carbons lined up in a row, And then there's branched hydrocarbons that have their carbons possibly in a t formation or a y formation instead of being all Straightly lined up.
Jam:Okay.
Melissa:Okay. So that's a a little concept you can just have and keep in your pocket.
Jam:To have and to hold kinda thing.
Melissa:To have and to hold. And and we talked in-depth on the Episode about butter versus margarine. I think it was our 2nd or 3rd episode that we ever did
Jam:Super early.
Melissa:About the shape of hydrocarbon chains and how they sort of make a chevron and Yeah. The chevrons will fit straight into each other, that is for straight Carbon chains.
Speaker 3:Got it. Got it.
Melissa:But when they're branched, they don't fit into each other quite as well because they don't have that consistency Okay. In the pattern.
Speaker 3:Got it.
Melissa:Okay. So in our gas engines, in our gas tanks, we put hydrocarbons, but we put specific hydrocarbons.
Jam:Right.
Melissa:They're comfortable.
Jam:Putting butter in there, obviously.
Melissa:Putting butter in there. Yeah. I think butter might be a little too big. So, on hydrocarbon, the molecules would be too big. Would be too big.
Melissa:Oh, okay. The liquid of it. Sorry. So hydrocarbons usually come from petroleum, and that's another way of saying crude oil.
Speaker 3:K.
Melissa:So crude oil, also known as petroleum, is literally just a mixture of hydrocarbons, and it goes all the way from carbon one all the way up to, like, carbon 20 or more. Okay. So carbon 1 would be methane. Carbon 20, I don't even know the name of it off the top of my head.
Jam:Okay.
Melissa:And some of them are straight change, and some of them are branch.
Jam:Let me guess. Like, it's, like, what is that? Just a guess.
Melissa:I think 12 is doe decane, so I feel like there might be a
Jam:Oh, that's so it's a lot weirder than I than I thought.
Melissa:Well, decane is 10. So doe Decade is 210.
Jam:Oh, interesting.
Melissa:I think.
Jam:The decade decade?
Melissa:Oh, yeah. Decade decade, that could be.
Jam:So 10 was 10. Yeah.
Melissa:Okay. Now I have to look it up. Short pause while I look this up. We're back with something I've I've maybe heard, but have never said before in my life, I'm sure. So 19 is Nana decane.
Speaker 3:Okay.
Melissa:So all those make sense. Dodecane, tridecane, tetra decane. All the teens make sense to me. 20 is EI Ossein.
Jam:What?
Melissa:It's e I oh, there's a c in there. Sorry. Eicossein. Okay. E I c o s, and then -ane is the suffix that says that it's all fully saturated, so no double bonds.
Melissa:So eiose is, I guess, e I eikos. Sorry.
Jam:Eikos.
Melissa:Eikos is the prefix, Which I don't think I've ever heard before. So for all of our chemists in there who are interested
Jam:Maybe it's just No one can really say it very well.
Melissa:That is
Jam:the one probably why I haven't heard it. Yeah. And whatever could have, just skip right over. They're like, and, Skip
Melissa:right over. I'm gonna go
Jam:back has 20.
Melissa:You know, I
Jam:didn't say that instead.
Melissa:I'm gonna go back to my own kid book that I teach out of and see if it's in there, and I just ignored it all these years. Okay. So you you have petroleum, which is also called crude oil Mhmm. Which they have Carbon chains, carbon 1, all the way up to carbon 20, and even above that. Okay.
Melissa:And they will separate out these based on their boiling points. And So carbon chains with similar number of carbons will have somewhat similar boiling points. I mean, branch versus straight chain is different. But K. It's close enough.
Melissa:So, Typically, based on the boiling point, carbon 1 through carbon 4 are kind of grouped together as natural gas, bottled gas, or, like, something you'd hook up to your Your grill, like butane has 4 carbons.
Jam:Okay.
Melissa:And then carbon 5 and 6, those are, usually solvents that are gonna be used, like, a chemistry lab or an industry. And then when we get to, anywhere from carbon 5 to carbon 10, That is gonna be more gasoline stuff. And then carbon 12 to 18, that's kerosene, jet fuel. And then Carbon 20 and higher is gonna be more like mineral oil. So they start to get into oily things, grease.
Melissa:And carbon 20 and higher also paraffin wax, asphalt. So those are not really, like, volatile liquids the way of the other ones are. They're more oily substances as you would think of them.
Jam:Interesting.
Melissa:Mhmm. So they'll separate those out based on their boiling points. They use a distillation process. So basically, they boil them and collect the gases and cool them back down into liquid.
Jam:Okay.
Melissa:So that's how they distill petroleum. And so if we have roughly from carbon 5 to carbon 10 chains being suitable for gasoline, then that's not really enough when it's naturally occurring for us to fill our actual demands for gasoline.
Speaker 3:Okay.
Melissa:So what will happen instead is they'll get the larger branch chain like carbon 12 and up and do something called catalytic cracking where they use Catalysts and heat sometimes, and they will crack, quote, unquote, those molecules apart and make them smaller so they're more suitable for gasoline.
Speaker 3:Okay.
Melissa:Okay. So your gasoline then is made up of a variety of different hydrocarbons
Speaker 3:K.
Melissa:That are in that range from carbon 5 to carbon 12, and they're sourced either from straight from petroleum or After the petroleum has been separated out into different fragments based on boiling point, those higher chain ones will be broken up into suitable for gas ones.
Speaker 3:Got it. Got it.
Melissa:Okay. But some of those are branch chain and some of those are straight chain. And, actually, straight chain hydrocarbons are not as good in the combustion setting of your engine as branch chain hydrocarbons. Branch chain hydrocarbons are Maybe a little bit more controllable. Sometimes they say more stable, which I think the phrase just being more stable is a little vague in this setting.
Melissa:But Right. They They act in a way that you would expect them to do. The more highly branched ones will ignite when they're supposed to ignite, and they fully ignite, and they do that very consistently. And so the car is working really smoothly. They burn very smoothly.
Speaker 3:Okay.
Melissa:Some of the straight chain ones will either ignite too soon or they ignite aft they don't fully all the gas isn't fully ignited, so then there's some leftover that will ignite again as, like, a secondary explosion at a time when you don't want it to do. Okay. So any extra explosions when they're not supposed to happen According to the car is something known as knocking.
Jam:Right.
Melissa:And knocking is bad. It can put stress on your engine because it's Basically putting out energy when energy is not supposed to be putting in.
Jam:Right. Right.
Melissa:So it can be stressful on the car.
Speaker 3:Okay.
Melissa:So initially, what they did to prevent knocking for some of these having, more branch chains present is they added Lead derivatives that were called anti knocking agents.
Jam:Okay.
Melissa:And once they realized that lead is really bad, that it shouldn't be just out in the air Because it gets into our system and people can even get lead poisoning, and it can even in small quantities, it can sort of make you sick or lower your immune system. They realized we shouldn't have that. So that's why gas is now called unleaded.
Jam:Right.
Melissa:Okay. Are you tracking with me?
Jam:I am. That part, And do a little bit about the lead part, so that helped a little bit. Because that is confusing and kinda weird. But yeah.
Melissa:It is kinda confusing.
Jam:But I am tracking but having a secondary explosion of some kind, Secondary, the ignition or whatever is not good. We wanna avoid it. And having the kind that the the Non straight what'd you call it?
Melissa:Branch.
Jam:Branch chain is better.
Melissa:Branch is better. Less secondary explosions.
Jam:Behave us more consistently than what we want.
Melissa:Yep. Okay. Okay. So that's why we have unleaded gas.
Speaker 3:Okay.
Melissa:So we also have something else. When you go to the gas pump, it usually says regular unleaded, premium unleaded, and super unleaded.
Jam:Mhmm.
Melissa:Meaning, this is regular gas. This is premium gas. This is super premium gas.
Jam:Okay.
Melissa:And they have numbers beneath them. Have you ever noticed that?
Jam:I have. I don't I haven't paid attention to what they are, but I've noticed that they're there.
Melissa:They're usually in the eighties. The best one might be in the nineties.
Jam:Oh, yes. Yes. Yes.
Melissa:And that's Essentially, a rating of how stable the gas is or, in other words, how resistant to knocking the gas is.
Jam:Mhmm.
Melissa:So when they got rid of the leaded gas, they had to sort of come up with another way to know if it wasn't knocking. And there are some Anti knocking agents that I think they still put into guess, but what they did instead was make a scale, and they call it octane rating.
Speaker 3:Okay.
Melissa:I think that's confusing because as we talked about, octane is just a general name for a carbon chain that has 8 carbons in it.
Jam:Right. Right.
Melissa:So there's an octane rating that doesn't really have anything to do with the actual amount of octane in it. Okay. Right. Which is confusing to me. But I think in if you weren't an organic Chemist, and you're just in the gasoline industry.
Melissa:It totally makes sense.
Jam:Okay.
Melissa:But here's how it came to be, which this part I think is really interesting. There is a highly branched 8 carbon molecule.
Jam:Mhmm.
Melissa:Its official name is 224 trimethylpentane. So if you have any Ochem people out there, you can draw this out on a piece of paper and test your Ochem knowledge. But its, unofficial name is just isooctane because it's basically just a different arrangement of octane.
Speaker 3:Okay. So
Melissa:it's a highly branched 8 carbon molecule. That's the isooctane. The oct indicates 8 molecules. The isooctane indicates that it's mixed up. Okay.
Melissa:And if that was your only gas, if you put that into your car, it would just run smoothly. And there it would be very resistant to knocking and be very consistent. That would probably be the best guess you could get.
Speaker 3:Okay.
Melissa:But the return on investment for isolating just that one probably isn't very good.
Jam:Right.
Melissa:So what they did instead was make a scale where the smoothness of isooctane was 100, And then a straight chain, heptane, that is very knocking prone is 0. Okay. So On a scale from 0 to 100, the closer you are to 100, the more smooth burn you have with less knocking.
Jam:Okay.
Melissa:More similar to the 224 trimethylpentane or isooctane.
Jam:Okay.
Melissa:And the more knocking you have, if it's down by 0, the more it acts like just a straight chain Heptane, which is 7 carbons in a straight chain that are not gonna be very smooth in an engine. Okay. So what they've done is create this rating system, And they will test to see if the mixture of hydrocarbons acts more or less like that isooctane Okay. On the scale. And those numbers are literally a rating of how similar it acts between 0 and 100 to the very, very smooth iso octane.
Speaker 3:Okay.
Melissa:So more premium gas, it's like a 92 octane rating. I always assumed, Amit, it has 92% octane because I knew what octane was, and I saw that it was 92. But, honestly, 92 of just normal 92% of just normal straight chain octane would be a bad Gasoline. Mhmm. Mhmm.
Melissa:But what it does mean is it acts on the scale from 0 to 100 as if it was 92% of the Really good component with maybe just a small percentage, like, 8% of the not more knocking prone fuels.
Speaker 3:Okay. Okay. Got it.
Melissa:So that's what those octane ratings mean actually. It has nothing to do with the percentage of actual octane, but does this mixture of hydrocarbons act at this level of performance, which is equivalent to this on our scale.
Speaker 3:Right. Right.
Melissa:So You could have any number of carb hydrocarbons in there, any number of different mixture of molecules in there, but it needs to have a level of performance that will be Good for your car.
Jam:Right. Okay.
Melissa:So that's what gasoline is. All those percentages mean is, does this work well in your car or not? How smoothly does this gas burn in a combustion engine? Yeah. And other than that, it's just a mixture of hydrocarbons in that range that are good for gasoline.
Speaker 3:Wow.
Melissa:Isn't that interesting?
Jam:Yeah. That's crazy.
Melissa:I'd had no idea.
Jam:Yeah. That's nuts.
Melissa:I assumed gasoline was 1 hydrocarbon. And based on the word octane thrown around everywhere, I assumed it was one straight chain hydrocarbon of octane, and then there was, like, Imperfections, and that was the other percentage.
Jam:Yeah. Well, I I never really thought about I never really got very far into Trying to just suppose what octane could mean or
Melissa:Yeah.
Jam:What the different numbers mean also. I did think that, you know, unleaded Super and super premium, whatever they're called. Mhmm. I thought it was probably something to do with how efficiently it runs or just know, it seemed like or maybe I thought, like, oh, one's more pure. Right.
Jam:You know, just a basic understanding of that. But but never enough to think it really mattered or to have any idea What actually the difference would be? You know? Like, what makes one of them better than the other? That never got that far.
Melissa:Well and so then I was Wondering, are these really better for your car if you use the higher percentage? And what it actually said, I can put my reference in there, but 1 one had said that, honestly, because there's so much computer, regulation now, the computer can If it detects that there might be a knock or a secondary explosion that they don't want, they will delay the spark plug or they'll Send the spark plug early and basically control for that extra gas. So the computers in our car make knocking a lot less of a problem.
Speaker 3:Okay.
Melissa:But if you have a newer car that is supposed to be a high performance smaller engine, Like, some of the Subarus are turbocharged now.
Jam:Mhmm.
Melissa:And what that means is they I think they put a little bit more fuel in, and they're more prone to knocking.
Jam:Okay.
Melissa:They put more fuel and air in so that it has a more powerful initial, acceleration, but without Makes it a more powerful engine, but without having to make it bigger and less good for the environment. Those some of them require a specific rating of octane because they need that insurance that it won't knock because otherwise, they are very prone to knocking because they have different conditions. Got it. So some cars that are more high performance that have demise their engines to be able to perfectly function need the insurance, basically, that they're not gonna be knocking because that could put stress on the car. Some others will function better if they have the higher octane ratings, but they're not required.
Melissa:So you should always look at your car's manual to see what kind of gasoline Is recommended or if it's required or if it really just doesn't matter.
Jam:Yeah. What's hard with that is, like, I think a lot of us, including myself, before Unshane, the chemistry of it. If someone was to say, like, oh, you really should be putting this gasoline in there. I think, like, I don't know, man. Are you just trying to get me to spend more money?
Jam:You know?
Melissa:Yeah. There's
Jam:always that doubt there where I'm
Melissa:just like Yeah. I'm like, does premium really do anything? I don't know.
Jam:I probably should look into that for the The cars we have.
Melissa:But But it doesn't say either that I looked to try to find if it really does improve your gas mileage or the function of your car. And if your car is rated for any of them, it didn't seem like it made that much of a difference. Like, it might just be more smooth, and it might help a little bit with the longevity. But As long as it's rated for all 3, that's fine. But some cars are not rated for all 3,
Speaker 3:and they
Melissa:need the high performance, the higher octane rating for their engine specifically. So you should look at that because it does matter because the knocking could really mess with the longevity of a system that's designed to function on the higher octane rating.
Jam:Okay.
Melissa:Isn't that interesting? Yeah.
Jam:That's kinda crazy. I'm trying to even figure out how to rap. Like, I get it, but how do I explain it? You know?
Melissa:This was For me, this episode was actually I was so interested, but I did have a hard time communicating because I felt like I very much took it into, like, a chemistry brain that already knew what octane was and that understood the different carbons on petroleum, and All that made so much sense to me that I was like, oh, this makes great sense. And then I tried to explain it, and I was like, this is kind of hard to explain. So if it felt like I just gave, like, a wall of information at you, maybe That's why. But it was hard to explain, but once I got it, I was like, this is fascinating. Yeah.
Jam:Yeah.
Melissa:So I thought it was really interesting because I didn't know how a car engine worked before, and I had no idea what gasoline was, and I had no idea what the different ratings of meth. So I learned a ton on this one, and it it's so organ it's organic chemistry specifically too Mhmm. But I feel like I really should have learned this sooner, and I wish I could have even taught my students about it, you know, as an everyday life example, but I just I'd I just never knew.
Jam:Yeah.
Melissa:Which I you know, that's part of what I wish we changed about some of the way chemistry is taught, but this was fascinating to me.
Jam:Yeah. I think I can take a crack at explaining this. I think I get it, But there may just be there's a lot of layers here. It may say something wrong.
Speaker 3:But
Melissa:Yeah. I've basically put you in the position I put myself in when I was writing this episode. Yeah. I'm like, great. Now that you understand it, explain it back.
Jam:So let me start I think let me start with what you most recently said sort of in the workplace way backward. I think that might be easier for me Okay. A little bit. And I'm gonna sure try Sort of Cliff Note this thing and not have the explanation be, like, miles long. So
Melissa:Okay. I think that will be good. I hope I hope our listeners were able to hang with us, and I do think a CliffNotes version actually would be really helpful.
Jam:So let me just start with, like, The different ratings of gas. Mhmm.
Melissa:What
Jam:we see when we go to the pump, kinda starting there, is That the octave rate is the highest Mhmm. Behaves the most like The sort of optimal you could have all the same molecule Yes. Which are gasoline already is not that.
Melissa:No.
Jam:It's a lot of variety. But if you could, You had that highly branched
Melissa:Mhmm.
Jam:Hepta whatever to do with it.
Melissa:It was isooctane.
Jam:I saw octane, but it's a yeah. It has 8 carbons. Yep.
Melissa:Carbons.
Jam:Yeah. And highly branched. It behaves very consistently, very well. Great for engines.
Melissa:Right.
Jam:That's the the top rated.
Melissa:Right.
Jam:Where at at a100 if Mhmm. If we're on a scale of 1 to 100 or 0 to a100. Mhmm. 0 is The worst, like, really not ideal for engines could maybe work, but would knock like crazy.
Melissa:Yes.
Jam:And really not work well long term at all.
Melissa:Right.
Jam:And, obviously, none of the gas things we could buy are that low.
Melissa:Right. No. There are.
Jam:Like, eighties nineties.
Melissa:Yes. Oh, and I forgot to say I got that I learned that from the US Energy Information Administration.
Jam:Nice.
Melissa:So, shout out to that Black government entity.
Jam:So we have these different choices that one behaves At the highest end, the most super one behaves the best for our vehicles as the most consistency is most like it had the highly branched
Melissa:Right.
Jam:Octane hydrocarbon. Mhmm. And then as you go further down, it gets a little less like that.
Melissa:Yes.
Jam:And but all of them actually just have a lot of variety of hydrocarbons in there because that's just more realistic. And to make it all be the same would be probably dumb and expensive.
Melissa:I think so. Yes. Yeah. That was my understanding. There could be someone if there is someone who is in the oil gas industry, I'd love to hear about it.
Melissa:But my understanding was, Oh, this one is the best. It's highly resistant to knocking, but it's unrealistic to get a pure version of that to put in our car.
Jam:Right.
Melissa:So instead, we get fuel that that can be at that performance level based on the mixture that it has.
Speaker 3:Okay. So that's
Jam:where we are. And to go up 1 step Further back, kinda early in the episode, just talking about hydrocarbons in general. Mhmm. There's a wide range of them, And some of it's just very different even, like, ways that they are found in nature, ways that they, like, naturally sort of present themselves in a substance. Like, some are, Like like, more liquidy, some are, like, released, like, gunky, like, waxy, things like that.
Jam:Yeah. So with that being
Melissa:Methane gas all the way to petroleum jelly that you put on your lips, that's Vaseline. That's the range of hydrocarbons.
Jam:Goes from gas to liquid to goopy liquid
Melissa:to Yeah. Yeah.
Jam:And so Goopy is the first word they get
Melissa:in mind. So good.
Speaker 3:But the
Jam:fact that that's the case means that we could take any of those and Chemists with their brains in their Mhmm. Heads can make the the ones that are not ideal for cars Mhmm. And do stuff to them to reorient the hydrocarbons to break the chains a little bit or whatever to make them more in that ideal range, which was in the 5 to 12?
Melissa:10. 5 to 10,
Jam:I
Melissa:think, is the ideal range for cars. So anything above that. They usually break them just, like, break bonds is my understanding, but there are different ways. That's called cracking. Like, imagine Cracking the molecule.
Melissa:There are different ways to crack.
Speaker 3:Okay.
Melissa:Either catalytic cracking or thermal cracking, And some give more ranch chains, and some give more unbranched chains. It's complicated.
Jam:Yeah. So they do that With the different variety of hydrocarbons we have Mhmm. To get into that range, the 5 to 10 range, because it's just there's not just a ton Naturally occurring that are already in that range.
Melissa:Yeah. Not enough to fuel all of our cars.
Jam:Yeah. And to go 1 step more granular, Where you kinda start in the episode was just this the different ways that carbons and hydrogens can be, bonded together in molecules.
Melissa:Mhmm.
Jam:And the variety is there. There's patterns. Mhmm. But, carbons want to have Four things bonded to it ideally. Yep.
Jam:Thought I was looking for that. And so depending on how many carbons there are, it has only so many available Places for other hydrogens to be as well, but it wants to have 4, things bonded to it. Yes. And so we just get a lot of options. Very simple, like 1 carbon, 4 hydrogens.
Melissa:Right.
Jam:Or, like, 20 carbons and however many hydrogens can fit on the extra bonds. And so just the the tons of different variables you could have of ways to combine those 2 basic elements
Melissa:Yeah.
Jam:On the on the periodic table And the ways they want to work together and link together Yeah. Can occur in a bunch of different ways.
Melissa:That's why I love organic chemistry. It's like you just take carbon and hydrogen and arrange them in so many different ways, and you get gasoline. You get life saving medicine. You get food. I mean, you get all kinds of Different Yeah.
Melissa:Molecules that all have such different properties. It's so beautiful.
Jam:Yeah. It's kinda crazy. It's crazy just think of something as complicated as gasoline being like, This is basically what it is. It's carbon and hydrogen. It's erases in different ways, but that's it.
Jam:You know?
Melissa:Right.
Jam:It's weird that we just can know that.
Melissa:Great. And carbon like, carbon dioxide is also carbon, but not with hydrogens. Yeah. You know? And then sugar is carbon, hydrogen, and oxygens.
Melissa:And so it's like, These molecules seem so familiar, but also, like, they're they can be the thing that cause an explosion in your car to make it run. Yeah. I don't know. You know? It's just There is so much beauty in the versatility of carbon and hydrogen, especially if you throw in a few oxygens or nitrogens here and there.
Jam:Yeah. And that's, I think, all I got. I I could go into the whole engine explanation, but I feel like that might be
Melissa:That's a little bit of a side.
Jam:Too much, and we we kind of know a lot of us lay people know at least a tiny bit about The piston engine thing. Right. Instead of just saying that the explosions happening in there is what's powering it Right. Is a little more relatable. But And that's it?
Jam:That's
Melissa:That's it. Yes. So, basically, hydrocarbons run your car. You have a variety of them, And the ratings are just a performance rating of knocking versus anti knocking. The less knocks you have, Probably a little bit more efficient on your car, but it's not the end of the world unless you have a car that requires one that's more resistant to knocking.
Melissa:Yeah. And they figured out the best one that's very anti knock very knocking resistant, And they made some standards and turned that into a scale of 0 to 100, and that's what those little numbers mean. That's crazy. I just thought of why
Jam:you're saying that. The analogy that wouldn't actually help most people.
Melissa:Okay.
Jam:But I just I'll throw it out there as, like, the I'll give you the guys the the short version. But I just realized that this is very similar to if anyone's, like, a sort of a finance nerd, especially about The 2008 housing bubble financial crisis in the US Okay. Affected everywhere. The way that banks bundle together mortgage bonds It's probably pretty similar to the octane reading in the sense that, like Interesting. These triple a rated mortgage bonds were supposedly, like, Filled with really good, you know, high quality mortgages, unlikely to default, and then you went further and further down, And I'm a little bit of a nerd about that stuff.
Jam:And I'm a little bit of nerd about that stuff. The Big Short is a movie that explains that really well.
Melissa:I've never seen that.
Jam:So for the 2 of you I've seen that movie and are interested in that crisis. You were like, oh, that makes sense.
Melissa:Yeah.
Jam:The rest of you, you're like, great. Another thing that
Speaker 3:I don't understand.
Melissa:Yeah. I don't I feel like it's hard for me to think of a non chemistry explanation, but sometimes in chemistry, a similar thing is, like, You can use known samples and, test the color of them. I think you do this in pool stuff too, where it's like, We develop a curve or a standardized, system that we're like, if if there's this color, then we know there must be this concentration of this thing. Yeah. And I feel like it's kind of similar to that where it's like, okay.
Melissa:Well, it's knocking this much, so that's Similar to if we had 82%. Right. It's knocking this much, so that's similar than if we had 92% of the really good You know? So it's like Yeah. It's comparing it to a known sample, sort of.
Jam:Mhmm. Mhmm.
Melissa:But but we do that in chemistry too. So I was like, that's not a good everyday life example. And there's not a lot of everyday life examples where you're, like, Comparing something on a scale to then, like, extrapolate that back to what? I don't know. Yeah.
Melissa:I was like, this is very weird. And then also just Oh, there was this 18 carbon thing that's really, really good when it's like, what does that even mean? I don't know. It was I was getting very philosophical when I was trying to explain it. Yeah.
Melissa:So I'm glad that you found a good that is a good Analogy. Even if you don't care at all about that, I don't know at all about the finances of the 2008 housing crash, But I do understand bundling a bunch of different things together and, like, oh, this is a high likelihood of success, and this is a lower likelihood. Yeah. That's cool. Okay.
Melissa:Well, great. We did it.
Jam:We did it.
Melissa:We learned about what gasoline is. This is something I have wondered about, and Every time I tried to look it up, I felt like it was gonna be hard Mhmm. For a long time. And so I'm excited that that I have learned this
Jam:I'm on I'm excited too. It's like, I just use an everyday thing. Like a lot of our topics, it's the whole point. But then this one is everyday and Seems more like a black box. Yes.
Jam:Seems more Yeah. Difficult to to figure out.
Melissa:This is also our 1st full episode back. So if we're A little rusty, that's part of why too. But we did wanna tell y'all about something kind of fun that happened while we were on our, Quote, unquote break. It was more of a break for some of us than others Yeah. That Jam and my husband, Mason, have been working on together.
Jam:Yeah. So we've talked in the past about how much of a coffee nerd I am, even to the degree of roasting my own beans. And, actually, there's been a couple of times, I think, at least 1 or 2 listeners have asked, like, can I get some of your coffee? And I know one of our our friend to the show, mister Hollis, he's asked before too.
Melissa:Yes.
Jam:But so what Mason and I have been working on is, basically, I'm bringing him into the whole coffee roasting game.
Melissa:Mhmm.
Jam:And we are tackling the same together and trying to just make it a lot more legitimate. So we Basically, now actually have a coffee roasting business.
Melissa:You upgraded your coffee roaster.
Jam:Yes. We upgraded the roaster, and now we're a lot more of A we're not just a hobby that I had anymore.
Melissa:You're in you can ship around the United States? Yep.
Jam:We can ship coffee to the US. And We mostly sell locally, but we wanted to open up shipping for some friends and family who don't live nearby and for anyone on the podcast who wanted to buy some coffee as well And people who may just stumble across us on the Internet, we would like to share good coffee with everyone. So
Melissa:So how can people get good coffee?
Jam:So it is called Good Coffee, by the way. I was like, a pun before you guys knew it was a pun. So our our brand is called Good Coffee. So g o o d e, Good.coffee on the Internet. That's our website.
Melissa:On the Internet? Yeah. So that's been Both of our fun thing because it's been hard for me to keep this secret. I'm so excited. Yeah.
Melissa:And it means that a lot of times when we're over here recording, Mason can be roasting, or Mason comes over to roast coffee, and it gives us a chance to spend even more time. Yeah. Our families to spend even more time together, so that's really Fun. Yeah.
Jam:It's kind of funny because, obviously, Melissa and I have been doing this project together for a while for, like, 3 years now.
Melissa:Yeah. A little
Jam:over that. And then Now Mason and I having a project together has been really fun too. And so it's just, yeah, it's just it's just fun to get to hang out and and work on fun things with the people that you like to hang out with anyway. Yeah. So that's kinda the whole that's the the vehicle of chemistry for your life and the vehicle of good coffee is just excuses to get to hang out.
Melissa:Yeah. Jim told me that he wanted to start a coffee business with Mason so he could hang out with Mason more. So that's literally the The reason. Yeah.
Speaker 3:Yeah.
Melissa:Awesome. Well, that's a very fun thing for this week. So we're just gonna leave that as sort of our end of the Episode of weekly update, so go check that out. It's kind of a new business, so, you know, who knows what's gonna happen after we put it out on this episode.
Jam:Bear with us. Be patient a little bit. And then give us feedback. We'd we'd love to have it. So Yeah.
Jam:There'll be some early customers, just so you know. So you're kind of A little bit in the beta, if that makes sense.
Melissa:Yeah.
Jam:But we'll we are happy to let you guys try it out and to give us some feedback.
Melissa:Yeah. Awesome. Well, thanks so much, Jim, for starting a coffee business with my husband. That's been fun to be a part of. And thanks for coming and learning about how gasoline works, And thanks to all of you for, 1, especially to Julian and Sam for giving your episode ideas, but also for all of you for bearing with us on our 1st episode back as we Talk about the chemistry of gasoline.
Jam:And thank you for teaching us and for delving into this difficult topic and helping make sense of it for the rest of us. If you have an idea like Sam and Julian did about gasoline and octane ratings and all that kind of stuff, Please reach out to us on Gmail, Twitter, Instagram, or Facebook at Kem for your life. That's Kem, 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/chem for your life, or tap the link in our show notes to donate the cost of a cup of coffee. If you're not able to donate, you can still help us by subscribing to your favorite podcast app and rating and writing our review on Apple Podcasts.
Jam:That also helps us share chemistry with even more people.
Melissa:This episode of Chemistry For Your Life is created by Melissa Colini and Jame Robinson. References for this episode can be found in our show notes or on our website. GM Robinson is our producer, and we'd like to give a special thanks to s DeWitt who reviewed this
