all right esters um esters are basically things that are what we use them for like in real life is for smells for artificial sense so we're going to take a look at some well-known artificial scents and then we're going to take a look at the actual reaction to create an ester so typically things that have artificial scents like perfume lotions um gum is another one here um uh like that wintergreen um uh wintergreen um uh a smell of of gum or taste of gum um is methyl salicylate which is a very very common ester it gives you that sort of like peppermint tea smell um most of esters have like either like a fruity or some sort of like sweet smell so you can see here like um if i'm if i'm going to mix an alcohol with an acid so these are acids on this like left margin these are alcohols across the top i'm going to get an ester so esters that smell like these are mint leaves so these are all of the um hexanoate heptanoate those are all um uh acids that will give me like a pepperminty smelling we've got coconut we've got like floral smells in here oranges so um why i wanted to point this out is because there's also things like um like there's a candle here there's red wine there is like glue up here um uh let's see is there anything this is wood i mean i guess actually wood's natural forget i said that one um i can't tell what that is but like i said perfumes lotions gums none those things aren't grown right they have to be made which means you have to add esters to them in order to give them the smells that you want so right now in like uh in the industry i guess the industry related to consumer products there's a big divide between whether artificial scents are bad whether you should be extracting them naturally or if you should be making them artificially um and honestly it honestly depends on what we're talking about if you're ingesting them you might want something that's derived naturally that means instead of making the um using the alcohol and the carboxylic acid to make the ester um like say for an orange like instead of using the octal acid or alcohol and the ethanoate acid to make that orange smell um instead of using octo to make the octal ethanoate ester which is that orange smell maybe you just get an orange and you extract the orange through the rhine or through the juice or something like that you extract it naturally rather than getting the octanol and the ethanoic acid it would take to make that um to make that ester uh a lot of your food products tend to have um naturally store sourced things like you'll buy things and it says like naturally organic or something like that which means again that it's not made like in a lab but a lot of your like lotions and perfumes and colognes and i don't know what else has like an artificial scent um that's not a consumable any of that kind of stuff candles they all tend to use artificially made esters and sometimes those products are absorbing into your skin and sometimes they're not and the ones that are not probably don't matter really the ones that are are the ones that people tend to like want to think about because when you think about like cleaning products like soaps or um or even like face washes like things you're gonna use in your body cleaning products sometimes you want might not want something naturally sourced because there's more of a chance of like irritants or allergens versus something that was made in a lab you know exactly what it is versus something that you're going to absorb into your skin maybe you want something that's more natural because you don't want to put chemicals in your body so there's a lot of debate right now on this specific topic and this is this is really why it's because there's two ways to get esters you can make them or you can naturally sort of extract them from where they naturally occur the type of reaction is called a condensation reaction when you're making an ester it is a very delicate process it's made by mixing alcohol and a carboxylic acid when you have too much alcohol it starts to smell like a cleaner a lot of cleaners household cleaners have alcohol in them i think we learned that this year um with covid or if this is next year than last year with covid um but i uh i think we we learned that in our recent history that alcohol can kill bacteria we've seen that in like the hand sanitizers they have to be 70 alcohol in order to be functional so um yeah alcohol smells like our cleaners because that's that's what is in cleaners is alcohol so uh when you're making an ester which is supposed to smell good and fruity and sweet and flowery if it smells like alcohol it means you had too much of that if it smells like cleaner i'm sorry it means you had too much of the alcohol now if it kind of smells like stomach bile or or like throw up that means you have too much of the acid acid is a very rancid smell um so like i said it's a very it's very hard balance to get an ester um because it's a very delicate process it takes just the right amount of alcohol and just the right amount of acid in order for the ester crystals to sort of form and to get those um nice scents we used to do this as a lab but we don't do it anymore because um hexane is the solvent and uh it's just a it's a chemical that once when inhaled it can it can do some damage to your lungs so we don't do it anymore um but this is the reaction where you have so i have methanol here it's an example of an alcohol we have our carbon with our oh no double bonded oxygen nothing like that so we know it's an alcohol it also ends in oil so i know it's an alcohol and then my butanoic acid i'm going to add those two together again it ends in oic acid so i know it's my acid it's got the oh as well but this time it has the double bonded o so that's the difference between the alcohol and the acid is that double bonded oxygen and so to make the ester we call it a condensation reaction if you remember it was condensation reaction because it makes water when you hear condensation hopefully you think of producing water which is what it does we take the h off of the alcohol and the o-h off of the acid and we make water down here and then right where we took those off we attached so that oxygen here will attach to this carbon here and that's what you see down here and that makes our ester and then we use the names of our alcohol in our acid to get the name of our ester so on our alcohol we drop that ending in add yl that's how we got methyl and then butanoic we drop that ick and we put eight so butanoic becomes due to no h so that's how we got this name down here for the ester methyl butanoate so again it's called a condensation reaction because we're taking out the water and then we're attaching that oxygen and that carbon together to get the um ester you in your notebook you will have to do some of these i did a few examples for you and then you will need to do the rest