hello everybody my name is Iman welcome back to my YouTube channel today we're going to continue our lecture on nomenclature and we left off at objective two which is hydrocarbons and alcohols now hydrocarbons are compounds that contain only carbon and hydrogen atoms alcohols on the other hand they contain at least one o h group now here in this section we're going to explore the naming of hydrocarbons and alcohols starting first with alkanes alkanes are simple hydrocarbon molecules with the formula CN h2n plus two it's just going to be carbons bonded to carbons and hydrogens through single bonds the names for the first four of these compounds so one carbon is methane two carbons ethane three carbons propane four carbons butane so methane looks something like this one carbon with four hydrogens propane for two carb ethane for two carbons looks like this carbon carbon and then each of these has hydrogens all right then we have propane for three carbons this looks like this carbon carbon carbon and these are all hydrogens I'm not going to write them out explicitly and then butane is four carbons and their respective hydrogens all right we can draw these also in bond line as we've been doing so far since that's more of a simple way of of drawing molecules here now after four carbons alkanes with more than four carbons actually have a simpler naming pattern in which the name is the Greek root describing the number of carbons followed by A and E all right so for carbons for more than four carbons like five we have we take the Greek root for five which is pent and we just add a and e at the end so five carbon chain is called pentane six carbon chain six is hex Add A and E hexane and so on and so forth I would recommend making sure you know the Greek group four numbers five through twelve just to be safe for the MCAT now that's alkanes again are named according to the number of carbons present using that Greek root followed by the suffix ain't all right now what about alkenes and alkynes while the MCAT does not explicitly test reactions of alkenes or alkynes you still might see the suffix e and e for alkenes and y and e for alkynes all right which signify double and triple bonds respectively now keep in mind that many of these compounds will also have common names and it's going to be vital to know these common names as well we're going to cover any common names that we may need to know in this lecture all right alkenes all right are alkenes are double bonds all right and alkynes are triple bonds now the double or triple bond is named um like a substituent and is indicated by the lower numbered carbon involved in the bond the number can precede the molecule or it may be placed near the suffix so let me tell you what I mean all right let's have this five carbon chain one two three four five and there's a double bond right here all right now we want to number this chain it's five carbons all right so we're thinking pentane right but there's a double bond so don't get too excited now let's number this really quickly so that the double bond has the lowest number one two three four five all right so if it was just a five carbon chain it would be called pentane but there's a double bond so we have to replace the A and E with e n e all right so pentene now we're not done we have to number it like we would a substituent all right this double bond is out of two so we say two pentene all right another way of doing it like I said it may be placed um near the suffix so you can actually write 10 to in all right either of these forms is correct at the end of the day it's more of a preference sort of thing all right now if there are multiple multiple bonds the numbering is going to be generally separated from the suffix all right so for example if we had two double bonds one here and one here the name of this molecule would be two four two four pen to die in because there are two of them all right Penta diene all right so that's how we would number it if there was multiple double bonds or same goals if there are multiple triple bonds all right so to summarize alkenes are named by sub by substituting e and e for the suffix and numbering the double bond by its lower numbered carbon alkynes substitute y and e with the same numbering habit all right so far so good all right now what about alcohols alcohols they contain a hydroxyl group this is an o h Group which substitutes for one or more of the hydrogens in an hydrocarbon chain all right alcohols are named by replacing the e in the name of the corresponding alkane with ol so notice here we have this two carbons and an o h group two carbons is typically ethane all right but because there's an alcohol we're going to replace the E with o l this is ethanol all right the chain is numbered so that the carbon attached to the hydroxyl group gets the lowest possible number even when there is a multiple when there's multiple Bond present like a double or triple bond the hydroxyl group takes precedence over double and triple bonds because of the higher oxidation state of the carbon if the alcohol though is not the highest priority functional group so say for example a higher priority group like in Ketone is present then you would name an alcohol group or an alcohol substituent using um the term hydroxy all right so here we have ethanol as an example here's another example we have this is a one two three four five six seven carbon chain so you're thinking heptane all right but there's an alcohol group and we're trying to give it the lowest number the lowest number would be two so we would change the E to an ol so Hep to null and of course we have to associate this with a number all right so two heptanol now don't get too excited that's not the full name because there is another substituent right here there's a methyl group at position five so that's the first thing you want to list off are substituents so the name is actually 5-methyl and then you could put two heptinol all right again alcohols are named by substituting the the suffix o l or by using the prefix hydroxy if a higher priority group is present fantastic now dials can contain two hydroxy groups and they can be termed geminal if they're on the same carbon or vicinal if they're on adjacent carbons fantastic so that's objective too let's summarize it very very quickly all right alkanes are hydrocarbons without any double or triple bonds they have this General format alkanes are named according to the number of carbons present all right followed by the suffix a-n-e the first four alkanes are methane ethane propane and butane larger alkanes use the Greek root for the number um and then follow it with A and E then we talked about alkenes and alkynes they contain double and triple bonds respectively alkenes are named by substituting e and e for the suffix and numbering the double bond by its lower numbered carbons alkyne you substitute y and e with the same numbering and then the last thing we talked about is alcohols they contain a hydroxy group which substitutes for more for one or more of the hydrogens in that hydrocarbon chain they are named by substituting the suffix o l or sometimes by using the prefix hydroxy if if there is a higher priority group present and that alcohol group becomes a substituent all right alcohols have higher priority than double or triple bonds and alkanes so far all right fantastic now what we want to talk about next are aldehydes and ketones aldehydes and ketones are two classes of molecules that contain a carbonyl group which is just a carbon double bonded to an oxygen like you see right here that is a carbonyl and aldehydes and ketones are two classes of molecules that contain a carbonyl group now aldehydes and ketones differ in the placement of the carbonyl group how so well aldehydes um are chain terminating meaning that they appear at the end of a parent chain while ketones are found in the middle of carbon chains aldehydes and ketones do not have any leaving groups connected to the carbonyl carbon they are only connected to alkyl chains or in the case of an aldehyde hydrogen atoms all right fantastic so let's cover one let's cover one at a time let's start with aldehydes aldehydes have a carbonyl group found at the end of a carbon chain they have this carbonyl group they're always attached to a hydrogen and then they have one R variable group now because this is a terminal functional group that takes precedence over many others all right it is generally attached to carbon number one and aldehydes are named by replacing the E of the parent alkane with the suffix a l all right when the aldehyde is at position one as it usually is the case we do not actually need to include this number in the chemical name all right so here let me draw an example very quickly all right here we have four carbons one two three four I'm numbering one near the aldehyde all right so typically four carbons has the alkane name butane but this is not just an alkane we have an aldehyde so we place the E with an Al so we have butanal all right so that's the name of this molecule and again we don't need to include numbering because the aldehyde if it's the higher priority group it will be given put the position number one all right fantastic now methanol ethanol and propanol are referred to almost exclusively by their common names formaldehyde acetyl aldehyde and propylenaldehyde all right so this the the proper name for this uh if you were you know following IUPAC names there's only one carbon here you'd think methane and then you'd replace the E with Al so methanol except it has a common name that it's more likely to be referenced to buy and that's formaldehyde this is a molecule that you should know both the common name and the IUPAC name and the same goes for these two as well acetyl aldehyde is ethanol all right that's the common name acetylaldehyde all right this is propanel and the common name is propylion aldehyde all right we should know for these three molecules the common name and the IUPAC name all right fantastic awesome so with that being said let's talk about ketones now ketones contain ketones contain a carbonyl group somewhere in the middle of the carbon chain because this is the case we're going to always have to assign a number to the carbonyl carbon when naming ketones um ketones are named by replacing a and e in the name of the parent chain the parent alkane with the suffix o n e all right so instead of A and E we do o and E and just as when naming other compounds we have to make sure we give the carbonyl the lowest possible number if that is the highest priority group all right so for example if we have this kind of molecule all right it's a one two three four five six uh two four six carbon chain so we're thinking hexane all right but it has this Ketone so we have to replace the A and E with O and E so hexone all right but we have to also attach a number all right this is one two three so this is three hexone all right fantastic here we have a couple of examples so this is a three carbon chain so we're thinking propane all right but we replace this with um with with uh o and E and I guess I misspelled it here so we should write 2 Pro pone all right here we have one two three four carbon chain all right we have a four carbon chain so we're thinking butane all right but we have a ketone and we have a double bond all right now we want to number this double this Ketone comes as higher priority than the double bond so we're going to give it the lower number so if we're going to start here one two three four and so we have a ketone at position two we have a double bond at position three so we're gonna say three butene and then we're gonna write two o n e for the ketone all right two butene to own fantastic all right now in more complex molecules with higher priority groups that that will take precedence over the carbonyl for example like carboxylic acids would take precedence over aldehydes and ketones then what we have to do is we have to name aldehydes and ketones as substituents and we can do this using the prefix Oxo all right for both ketones and aldehydes if they are substituents we use the prefix Oxo all right fantastic so that's aldehydes and ketones let's move into carboxylic acids and their derivatives now carboxylic acids contain both a carbonyl group and a hydroxy group all right they contain a carbonyl group as a carbon double bonded to an oxygen and a hydroxy group an oh group on a terminal carbon now carboxylic acids like aldehydes are terminal functional groups therefore their Associated carbon is usually numbered one carboxylic acids are the most oxidized functional groups that appear on the MCAT with three bonds to oxygen only carbon dioxide with four bonds to oxygen contains a more oxidized carbon all right so therefore what does that mean that means carboxylic acids are the highest priority functional groups in MCAT tested nomenclature all right and all other groups are named as substituents using prefixes if there is a carboxylic acid present all right now carboxylic acids are named by replacing the e all right with OIC acid so here for example we have two carbons one two so we're thinking ethane all right but there's a carboxylic acid so we replace the A and E we replaced just the E I'm sorry we replace the E with OIC acid so this became becomes ethanoic acid that is the name of this molecule right here all right now also something else that's really important here just like we did with with aldehydes the common names for carboxylic acids can show up really often on the MCAT so what we have drawn here are methanoic acid ethanoic acid and propanoic acid all right but they are usually referred to more often than not by their common names so methanoic acid is also known as formic acid ethanoic acid is known as acetic acid and propanoic acid is known as probionic acid as well so for this you should definitely know for these three molecules both their IUPAC name and their common name for the MCAT beautiful now let's talk about carboxylic acid derivatives Esters are carboxylic acid derivatives in these compounds instead of having an oh group here you have an o r group all right where R is a variable group all right R is a hydrocarbon chain now esteronym nomenclature is based on the naming conventions for carboxylic acid the first term is going to be the alkyl name of the esterfying group think of this first term as like the adjective describing the Ester based on the identity of the alkyl group and then the second name is the name of the parent acid with oat replacing the OIC acid suffix so for example methanoic acid or formic acid would form butyl methanoate with exposure to butanol under appropriate reaction conditions all right so let's you know let's let me show you an example all right so here is an example we're going to have this right here all right carbon carbon carbon with it double bond to oxygen all right and this group is going to have an ethyl group all right so how do we name this well we're going to start off with this group right here all right the first term is the alkyl name of the Ester fine group all right so think of this first term as an adjective describing the Ester that's simply based on the identity of the alkyl group simply based off of the term the the r group right here all right this group is an ethyl group all right it's an ethane group but it's like we're thinking of it as a substituent so we call it ethyl all right now that we've named this we can look at the rest of this molecule it has one two three carbons so we're thinking three carbons propane all right but for Esters all right we're gonna we're going to convert the E to o a t e so this becomes Pro pain know it ethylpropan know it all right so that's how you go about naming esters fantastic what about a mods and see here we have an example this is propyl ethanoate this is methyl butanoate all right notice how methyl is the description of this R Group this is just a methyl group all right then we have one two three four carbon chain here so butane but we replace the E with o a t e beautiful now we can cover a Minds all right and my uh another group of carboxylic acid derivatives includes amines and in the mind the hydroxyl group is replaced by an amino group so a nitrogen-containing group these compounds they can be more complex the amino nitrogen can be bonded to zero one or two alkyl groups now amides are really are named similarly to Esters except that the suffix becomes a mind all right substituents attached to the nitrogen atom are labeled with a capital N all right and indicating that this group is bought is bonded to the parent molecule via a nitrogen all right these substituents are included as prefixes in the compound name and they're not numbered all right so here for example we have let's look at this one right here all right at the nitrogen right here of this amide group it has two methyl groups attached to it all right so we're going to say dimethyl all right we're naming it very similar to the way we named Esters we look at the R Group and describe that first all right so we describe the two groups that are attached to the nitrogen first dimethyl all right two methyls so we're going to have to put two ends that preface that first so n n dimethyl now after we got that part we can look at the rest of the molecule this has two carbons so we're thinking ethane all right but we replace the E with a Mite so ethane amide all right and we add that to the name so this is n n dimethyl ethane amide and that is the name of this molecule beautiful last but not least we want to discuss and anhydrates these are our final group of carboxylic acid derivatives in the formation of an anhydride um from two carboxylic acid molecules one water molecule is going to be removed excuse me many anhydrides are cyclic which may result from the intramolecular dehydration of a dicarboxylic acid anhydrides are named by replacing acid with anhydride in the name of the corresponding carboxylic acid if the anhydride is formed from only one type of carboxylic acid all right so for example this molecule right here all right is called ethanoic anhydride so this is formed if you if you cut it in half where the where the oxygen is here what is this this is one two carbons ethane all right how would you know that name this if this was a carboxylic acid you would name it as ethanoic acid all right but ultimately this is an anhydride so you would change the acid in that name to anhydride and so the name of this molecule is ethanoic anhydride now if the anhydride is not symmetrical then both carboxylic acids have to be named before anhydride is added to the name all right so for example this molecule right here if you cut it at the O you have two different molecules all right this one has one two three carbons and this one has two all right two carbons is ethane all right but we're pretending it's a carboxylic acid so we put ethanoic for this guy this one has three carbons so propanoic and instead of saying acid like we would for carboxylic acid we change the acid to anhydride so this molecule is ethanoic propanoic and hydride all right and with that we've covered all the naming for the groups the different functional groups we're going to see on the MCAT and here at the end what we see is a table that lists the functional groups that you're going to need for to know for the MCAT in order of priority with prefixes and suffixes carboxylic acids are the highest priority functional groups all right and in nomenclature you want to use the suffix if the functional group is the highest priority group in the molecule otherwise name the group as a substituent using its prefix all right so we have that for what it would be for alkanes alkynes alkenes alcohols ketones aldehydes amides Esters anhydrides and carboxylic acids and the Order of priority is carboxylic acids are highest priority followed by anhydrides then Esters then amides then aldehydes and ketones then hydroxyl groups then alkenes or alkynes and then alkanes all right and with that we have finished the lecture for this chapter on nomenclature in the next video we're going to tackle some practice problems together let me know if you have any questions comments concerns down below other than that good luck happy studying and have a beautiful beautiful day future doctors