Introduction to Organic Chemistry (AQA Revision Video)

[Music] hello my name is Chris Harrison I&#39;m for Mallory cheaters.com and welcome to this video this is a revision video for AQA in particularly look at the introduction to organic chemistry so basically just going to go through an overview of this topic it&#39;s just designed for revision ready to give you a brief insight into the topic to make sure that you&#39;ve covered most of things and you can the powerpoints that I&#39;m using here and you can purchase them you can get them from the link in the description box below the video and if you click on that link it will take you to the place where you can buy them from and later so this is very specific to a3 I am so we have the points here this is what it sees in the specification and so it&#39;s just making sure that you&#39;re able to and as you address these points so you can answer the questions in the exam ok so let&#39;s have a look first we&#39;re going to look at the types of formulas a few of these you need to know these formulas and it&#39;s really it&#39;s all about application in the exam of these so the general formula is basically an algebraic formula and it can be applied to chemicals in the family so for example alkanes alkenes and alcohols etc so you can see here that we&#39;ve got some examples of general formulas here so we have an alkene which is cnh2n plus 2 and we&#39;ve got alkenes which are cnh2n obviously we have the lack of the two hydrogen&#39;s there and then alcohols are cnh2n plus 1 o H so as long as you can state these general formula they&#39;re pretty important in case you&#39;ve got to be able to you know you&#39;ve got to know how to do that ok right so molecular formula so these are the actual number of atoms in a molecule or element so the molecular formula is basically just something like c2h6 so this is e same for example so these are the standards for whatever that you may see when you right now your chemical equations empirical formula this is very similar to make formula except this is the simplest whole number ratio of atoms in a compound now these look a little bit odd because they don&#39;t kind of fit so for example if we use the ething example used before that was c2h6 it&#39;s empirical formula is ch3 now you look at that and think well ad doesn&#39;t really look like because obviously carbon needs four bonds but remember this is just the simplest whole number ratio of a compound so and that&#39;s pretty important okay structural formula so this is the arrangement of atoms in a molecule without showing any of the bonds okay so there&#39;s no bonds being shown here so for example a fused Butte and voila basically we&#39;re fragmenting or breaking the molecule down into ch3 ch2 chunks so a butan one all is ch3 ch2 ch2 ch2 h notice there&#39;s no lines here to display the bonds just literally straight up there see formula X good little formula right scalia formula they show the bonds of the carbon skeleton only hydrogen and carbon atoms are not shown and but the functional groups are so these are a bit strange so here&#39;s an example this one&#39;s beauty and one all basically each one of these points here is a carbon with hydrogen attached to it so this is ch3 ch2 ch2 ch2 H so we&#39;ve got one two three four carbons with an O H on the end we use these in chemistry because sometimes the organics precision organic chemistry because well we do it in organic chemistry because the it can be right come take a while to basically draw your carbons and hydrogens etc so it&#39;s a lot quicker displaying it like a skeletal formula it looks like a lot of zigzags but actually the the each point here is a carbon with obviously the maximum number of hydrogens it can fit round it and according to where it is in the molecule so that&#39;s the skeletal formula and you displayed formula basically it shows the arrangements of all the atoms and shows the arrangement of atoms so all the bonds and the atoms in the molecule so for example this is 2-chloro pro and you can see here that we&#39;ve got a Z are all our carbons there&#39;s chlorine look sitting on the second carbon but notice all the bonds are being displayed we&#39;ve all been showing and all the atoms are so we&#39;re not doing CH 3 CH CL CH 3 we&#39;ll let you show it everything so it&#39;s all broken down okay that&#39;s called the displayed folder make sure you aware of that to eat that will ask these specific things okay that&#39;s a look at the homologous series so the homologous series of a group of compounds they&#39;re basically the same functional group and they have the same general formula as well so we need to know and obviously we need to be able to apply these and work them out so for example we&#39;re going to use the general formula to work out the Moloch the molecular formula of a compound so for example alkenes have this general formula cnh2n and n is the number of carbon atoms and the molecular formula of an alkene with 23 carbons is basically this so we&#39;ve got C 23 h2 times 23 because we&#39;ve got obviously and h2 n so n is just the number of carbons so that&#39;s going to be 23 so this is going to be C 23 H 46 so this is the general formula and we&#39;re using this to work out the molecular formula that we&#39;ve seen before now successive members of the same homologous series increases by CH 2 so for example the general formula for alcohols the cnh2n plus 1 or H so easy you&#39;ve got methanol ethanol look is in the same homologous series just adding an extra CH to propanol add an extra CH 2 butanol adds an extra CH 2 so these are successive members of the same homologous series so we need to know obviously the specific types of homologous series so alkanes they all ended Ain and for example butane there&#39;s an example though alkanes which are branched they have an alkyl group so for example it be methyl propane so this is basically an a methyl group on the middle carbon there as is a methyl propane through to sit on karl alkenes are they have the ending in E and E okay they example this propene CH 3 CH ch2 so basically just end it in E so it&#39;s pretty straightforward and alcohols they ended oh L so this is like an alcohol ethanol look there it is ch3 ch2 H s ml alcohols aldehydes ending out so that propane out for example and there&#39;s an aldehyde so CH o at the end ketones ended own so oh and E so that&#39;s propanone for example and so CH 3 Co CH 3 carboxylic acids they ended or Cassatt so for example butanoic acid so ch3 ch2 ch2 ch2 the end in this bit here KU c or h so look out for that that&#39;s the classic sign of carbocylic acid ecology no alkanes and these are things like you&#39;ll come across these and fluro chloro bromo io dough so for example bromo ething is this one here ch3 ch2 BR and the final one of cyclo alkanes so basically just put the word cyclo and front of it and end it in aid so for example cyclo pentene c 5 h 10 so make sure you know these functional groups are really important obviously naming them is going to be crucial you are going to be expected to name these molecules and so make sure you do know them okay so talk about naming and let&#39;s actually look at some so this is nomenclature which is the password for naming molecules and we use the I you pack rules and so I you pack is basically like a governing body but like FIFA for football so basically this is a FIFA for chemistry of PEC sorry so these basically govern the rules and naming molecules and naming the elements of the periodic table and it&#39;s got a very catchy name and I you pack it actually stands for the International Union of pure and applied chemistry yep you can see whether they&#39;ve called it IU pack instead basically and this is the global language of chemistry and they set these rules out and they&#39;re really handy because it allows us to name long molecules so the first thing they have to do is rename or find the length of the stem by counting the longest continuous chain of carbons so the stem name if it&#39;s got one carbon it Smith it it&#39;s to its east of its three it spoke for as beautify Vaz pen and sixes hex and you can go on and on you can keep on going and then you get seven eight nine two etc so basically you need to know the stem name so we start with the stem name so we find the longest continuous chain in this molecule the longest continuous chain is that one there in case that&#39;s four carbons really really important it doesn&#39;t matter even if it looks like a branch looks as though it&#39;s coming off another carbon you just need to find the longest continuous chain your molecule besides that enough if you don&#39;t find that your molecule will not be named right okay so functional groups on the molecule normally tells you the ending of the name we call it the suffix so then basically it also has an O H group this molecule here which means that this one will end in all because we&#39;ve got two after were two or h groups in this one okay so the third thing what you have to do is number the carbon chain so the functional group sits on the lowest possible carbon number now I can name this in two ways I can either name it one two three four or I can do it this way as this is suggesting one two three four and because I&#39;ve named it this way because my functional groups sit on the lowest number fine numbered it from here one two three four these are HS at sit in the fourth carbon now one is obviously lower than four so we named it from or we number it from this way round and then what have to do is make a note of the carbon number to the OHS attached to and place this number before the suffix and this is the type of butan one all and this one here so again we&#39;re going to put obviously one because it&#39;s sitting on the first carbon we put that before the suffix at the end okay so any side chains are side chains and less important functional groups are written as prefixes in alphabetical order okay so this is really important so in this case we obviously have a methyl group load is there we&#39;re going to meet the R group hanging off this third carbon carbon and three and finally if there is more life there are more to say more than one identical functional group or sidechain we put die tri or tetra in front of it so die for to try for three tetra for four so this one here is three me style boot on one one dial okay right but let&#39;s just break this down a little bit we&#39;ve got three nice I&#39;ll we&#39;ve got a methyl group they&#39;re sitting on the third carbon carbon number three butane because you&#39;ve got longest carbon chain is butan and one one because we&#39;ve got two alcohol groups sitting on the carbon number one so we call it one one and die that tells we&#39;ve got two of them all because we&#39;ll see it&#39;s an alcohol so make sure you&#39;ll be able to name that and look for the longest carbon chain okay mechanisms right so a chemical mechanism shows the movement of electrons during a chemical reaction now organic chemistry is all about mechanisms you have to be able to show them to show how reactions occur and the hours are crucial so you need to know about these hours so we use a curly arrow to show the movement of a pair of electrons and you&#39;ll see this throughout the rest of the organic chemistry topic and they always start from an area where there&#39;s lots of electrons could be a double bond or lone pair and in suit on the red arrow they&#39;re basically the end of the arrow is basically showing you where they move where the electrons are moving to and or it could be the formation of a new bond and sometimes it is so and free radical mechanisms and we don&#39;t require any curly hours you&#39;ll see free radicals in the halogen or topic halogen or alkanes topic but we don&#39;t need to know them for this so that makes it a little bit easier and a mechanism showing how an OHA is reaction reacts with bromo ething okay so let&#39;s have a look at this as an example so you can see here that we&#39;ve got a no h- and a bromo ethane molecule basically we&#39;ve got the lone pair now curly I was busy show this bit here look the electrons are moving from a lone pair to a bond or the transform of with the carbon so if you look that&#39;s going from an area where loads of electrons to adults positive carbon ok also this one&#39;s forming a bond here but also the curly ours can show how we can break a bond as well electrons are in this bond but the electrons are now moving onto the bromine here so the arrows are representing the same thing but they always start familiar with electrons you throw a lone pair of a bonds this is showing bond making this is showing bond breaking so it doesn&#39;t really matter and curly ayahs can be used to demonstrate both okay and obviously the final product in this case is just the example is reformed an alcohol here so this is a señal and a bromide iron as well and so yeah and the we did have sodium in here because we&#39;re going to react with sodium and if it was sodium hydroxide but it&#39;s a spectator ion doesn&#39;t actually get involved with the reaction okay so make sure you know mechanisms you&#39;ll see them quite a bit anyway in the organic topic later on which is just showing you kind of an introduction to it okay structural isomers so chain isomerism right you need to know about all these different types of isomers so structural isomers have the same molecular formula but a different structural formula ok so there&#39;s three types here that we need to know is chain positional and functional group ok we&#39;re going to go through each one make sure we know what the are we&#39;ll start with chain first so basically definitions are important here same molecular formula but different arrangement of the carbon skeleton okay so let&#39;s have a look at an example so here&#39;s pentane and an isomer of pentane could be to me sour buting now both these formulas have the same molecular formula and but the arrangement of the atoms as you can see is different so this one has just been shuffled around a little bit but if you count the number of carbons and hydrogens they&#39;ll be the same as what&#39;s in tenting so these are actually isomers of each other chain isomers okay right so let&#39;s have a look at positional isomers so these have the same molecular formulas it&#39;s the same as before but different position of the functional group okay of the carbon skeleton so positional look at the word before the word item a positional is the change of position of the functional group so here&#39;s an example this is pen and one all and the positional eyes from open and what all is pen unto are so the position of the alcohol group has moved is moved from the end to the middle not classic sign of a positional iseman and a functional group isomerism this basic again the same molecular formula of start with the same thing but a different functional group the word in front of the I Smith tells you what&#39;s changing since the functional group is changing so for example his pen twonny and basically we need to have a molecule that doesn&#39;t have an alkene in but has the same molecular formula and that can recently cyclopentane cyclopentane has the same molecular formula it spent money to count the number of carbons and hydrogens and you&#39;ll see that from there you can see crucially there&#39;s no double bond so it&#39;s a definitely a function of your basement okay you also get these types of isomers as well which are stereo isomers or also known as easy isomerism now these are a little bit tricky so stereo isomers stereo isomers have the same structural formula okay but a different arrangement of atoms in space okay so an example is an easy isomer okay that you need to know and you&#39;re skeptical as well but optical think of it is so you find that but you got stereoisomerism so we&#39;ve got a CC double bond okay and all these things do when you&#39;re looking at easy A&#39;s okay so we&#39;re looking for the alkenes and the atoms are bonded directly to this aisle flat their planar okay so the atoms can&#39;t rotate around this bond because it&#39;s rigid it can&#39;t move and this Bend you get some special type of isomerism which we call it stereoisomerism or easy so let&#39;s have a look at these two examples here so these are two stereo isomers of each other they have the same structural formula ch3 ch2 CH ch ch3 but we can&#39;t twist the double bond in order to turn one isomer into the other so if you look at this one there&#39;s three bonds this can&#39;t rotate so you can see this one and this one you can see the main difference is basically the CH 3 on this one is down here where is this one it&#39;s up there so because this can&#39;t twist I can&#39;t flip that one round to match this molecule here because that&#39;s fixed because I can&#39;t do that this molecule is different to this one and that&#39;s what we call an easier iseman so let&#39;s have a look so got these two isomers have restricted rotation around the double bond okay so we get easy isomerism when you have two different atoms or groups of atoms on the same carbon so if we look at these two here there it is look two different ones we&#39;ve got this one and that one these two are clearly different and these two are different to each other so that&#39;s where we get easier Daesan RISM if we have two hydrogens on the same side here hydrogen air hydrogen air we wouldn&#39;t get easier isomerism okay so we look at the two different groups so we can name these molecules as Y or Z and E stands for n Gagan which means opposite and and these are the same groups that are opposite double bonds and we can label them as Zed or soot salmon which means together and these basically the same groups on the same side of the double bond so let&#39;s label these ones so this one is their heads chewing because look the molecules or the the hydrogens or you could use these ones but the hydrogens are on the same side of the double bond that&#39;s both at the bottom so call it as their depend to e but look at the hydrogens here in hydrogens are now opposite the double bonds so we call this one e pen to e and it&#39;s pretty much as simple as that now it gets a little bit trickier when and we have let&#39;s say we have a groups which are the same so in the previous example we had the two hydrogens obviously ones if we don&#39;t have two hydrogens well then all we have to use something called the carnold prelog rules or also known as kip rules and now you&#39;ve got to be really careful with these okay so we use these conning gold prey log rules or CIP rules kibbles and when deciding for nice meteors ed when we have four different groups around the double bond so look at this example here you can see that we&#39;ve got four different groups unlike the previous one we have two hydrogens here now what we&#39;ve got is h @b r ch3 and a ch2ch3 attached from here so all these are different that&#39;s going to be really difficult when we&#39;re using the normal rules so what we do is you label the carbons with a double bond that&#39;s carbon one and car and two you can see that we&#39;ve related than there then what we do is you calculate the atomic number of the first element directly bonded to the CC bond this atom so the aten with the highest atomic number is given a higher priority now remember it&#39;s atomic number not mass number okay so it&#39;s the number protons the proton number of the atomic number so don&#39;t get them mixed up okay so look at these two obviously ch3 has an atomic number of six or the carbon sorry has an atomic number of six because look at the first element and bromine has an atomic number of 35 bromans got a bigger atomic number so it&#39;s given the higher priority so let&#39;s look at the other side so again carbon on the left there and has the higher priority it&#39;s got six and the hydrogen on the bottom there this one here hydrogen has a lower priority it&#39;s got an atomic number of one so the two higher priorities are actually opposite double bond so this is what we&#39;re saying here so the two high priority groups are on carbon 1 and carbon 2 are opposite sides of the double bond you can see they&#39;re opposite double bond there they are so in that case we call this one at e2 bromo 10 - 2 e the e bit tells us that is opposite the double bond ok so it&#39;s pretty pretty straightforward there ok so these are your and make sure you can obviously a sign these and you can use it&#39;s pretty straightforward just remember that this is the proton number not the mass number okay so you may have to check further down the chain though to work out the priorities and so let&#39;s have a look so here on carbon 2 there are two carbons immediately bonded to it you can see here there we go so these will have the same priority normally and so both have an atomic number of six and but if we look at the next up and down the chain there&#39;s another carbon on the e-file group so it&#39;s here there&#39;s the carbon and this has an atomic number of six but just a hydrogen on the methyl group on here which is an atomic number of 1 so basically obviously if we look at these ones this has got the higher priority on this side but look at this one the atomic number is 6 then 6 because we&#39;ve got 2 carbons this one is 6 then 1 so because this goes to 1 this is a lower priority and this one&#39;s a higher priority so just keep looking down the chain and just add the numbers up so the ether group takes priority this one here over the methyl group and so again we&#39;ve got two higher priority groups opposite the double bond so this one becomes an e1 bromo to meet I&#39;ll Butte 1e okay so again look down the carbon chain make sure you know how to do that and just a kind of trick you&#39;ve got to watch out for these isomers and make sure that you have actually drawn an item it&#39;s different sometimes they can get you to draw these isomers and you haven&#39;t just draw one with a different shape so and basically you need to find the longest continuous chain remember said that right at the start and doesn&#39;t matter the shape the shapes irrelevantly we&#39;re just looking at the longest carbon chain so let&#39;s have a look at this one there&#39;s pentane this one is still pentane it looks a little bit different but it is still pentane believe me and so you again look to the longest carbon chain and look at this one z butene and this one is still Zed butte to e okay and there is no difference even though the hydrogens are at the top on this one and them on the bottom here it is still there beauty so don&#39;t be tempted to draw this and call it something else okay to make sure you kind of look at that for them and that&#39;s it that is your kind of quick introduction to organic chemistry it just gives you an overview of the of the intro to organic chemistry topic for AQA again if you would like to and purchase this this PowerPoint you can and you can use it for whatever you want to do if you just click on the link on the description box for the video underneath you&#39;ll be able together there that&#39;s it bye bye

[Music] hello my name is Chris Harrison I&amp;#39;m for Mallory cheaters.com and welcome to this video this is a revision video for AQA in particularly look at the introduction to organic chemistry so basically just going to go through an overview of this topic it&amp;#39;s just designed for revision ready to give you a brief insight into the topic to make sure that you&amp;#39;ve covered most of things and you can the powerpoints that I&amp;#39;m using here and you can purchase them you can get them from the link in the description box below the video and if you click on that link it will take you to the place where you can buy them from and later so this is very specific to a3 I am so we have the points here this is what it sees in the specification and so it&amp;#39;s just making sure that you&amp;#39;re able to and as you address these points so you can answer the questions in the exam ok so let&amp;#39;s have a look first we&amp;#39;re going to look at the types of formulas a few of these you need to know these formulas and it&amp;#39;s really it&amp;#39;s all about application in the exam of these so the general formula is basically an algebraic formula and it can be applied to chemicals in the family so for example alkanes alkenes and alcohols etc so you can see here that we&amp;#39;ve got some examples of general formulas here so we have an alkene which is cnh2n plus 2 and we&amp;#39;ve got alkenes which are cnh2n obviously we have the lack of the two hydrogen&amp;#39;s there and then alcohols are cnh2n plus 1 o H so as long as you can state these general formula they&amp;#39;re pretty important in case you&amp;#39;ve got to be able to you know you&amp;#39;ve got to know how to do that ok right so molecular formula so these are the actual number of atoms in a molecule or element so the molecular formula is basically just something like c2h6 so this is e same for example so these are the standards for whatever that you may see when you right now your chemical equations empirical formula this is very similar to make formula except this is the simplest whole number ratio of atoms in a compound now these look a little bit odd because they don&amp;#39;t kind of fit so for example if we use the ething example used before that was c2h6 it&amp;#39;s empirical formula is ch3 now you look at that and think well ad doesn&amp;#39;t really look like because obviously carbon needs four bonds but remember this is just the simplest whole number ratio of a compound so and that&amp;#39;s pretty important okay structural formula so this is the arrangement of atoms in a molecule without showing any of the bonds okay so there&amp;#39;s no bonds being shown here so for example a fused Butte and voila basically we&amp;#39;re fragmenting or breaking the molecule down into ch3 ch2 chunks so a butan one all is ch3 ch2 ch2 ch2 h notice there&amp;#39;s no lines here to display the bonds just literally straight up there see formula X good little formula right scalia formula they show the bonds of the carbon skeleton only hydrogen and carbon atoms are not shown and but the functional groups are so these are a bit strange so here&amp;#39;s an example this one&amp;#39;s beauty and one all basically each one of these points here is a carbon with hydrogen attached to it so this is ch3 ch2 ch2 ch2 H so we&amp;#39;ve got one two three four carbons with an O H on the end we use these in chemistry because sometimes the organics precision organic chemistry because well we do it in organic chemistry because the it can be right come take a while to basically draw your carbons and hydrogens etc so it&amp;#39;s a lot quicker displaying it like a skeletal formula it looks like a lot of zigzags but actually the the each point here is a carbon with obviously the maximum number of hydrogens it can fit round it and according to where it is in the molecule so that&amp;#39;s the skeletal formula and you displayed formula basically it shows the arrangements of all the atoms and shows the arrangement of atoms so all the bonds and the atoms in the molecule so for example this is 2-chloro pro and you can see here that we&amp;#39;ve got a Z are all our carbons there&amp;#39;s chlorine look sitting on the second carbon but notice all the bonds are being displayed we&amp;#39;ve all been showing and all the atoms are so we&amp;#39;re not doing CH 3 CH CL CH 3 we&amp;#39;ll let you show it everything so it&amp;#39;s all broken down okay that&amp;#39;s called the displayed folder make sure you aware of that to eat that will ask these specific things okay that&amp;#39;s a look at the homologous series so the homologous series of a group of compounds they&amp;#39;re basically the same functional group and they have the same general formula as well so we need to know and obviously we need to be able to apply these and work them out so for example we&amp;#39;re going to use the general formula to work out the Moloch the molecular formula of a compound so for example alkenes have this general formula cnh2n and n is the number of carbon atoms and the molecular formula of an alkene with 23 carbons is basically this so we&amp;#39;ve got C 23 h2 times 23 because we&amp;#39;ve got obviously and h2 n so n is just the number of carbons so that&amp;#39;s going to be 23 so this is going to be C 23 H 46 so this is the general formula and we&amp;#39;re using this to work out the molecular formula that we&amp;#39;ve seen before now successive members of the same homologous series increases by CH 2 so for example the general formula for alcohols the cnh2n plus 1 or H so easy you&amp;#39;ve got methanol ethanol look is in the same homologous series just adding an extra CH to propanol add an extra CH 2 butanol adds an extra CH 2 so these are successive members of the same homologous series so we need to know obviously the specific types of homologous series so alkanes they all ended Ain and for example butane there&amp;#39;s an example though alkanes which are branched they have an alkyl group so for example it be methyl propane so this is basically an a methyl group on the middle carbon there as is a methyl propane through to sit on karl alkenes are they have the ending in E and E okay they example this propene CH 3 CH ch2 so basically just end it in E so it&amp;#39;s pretty straightforward and alcohols they ended oh L so this is like an alcohol ethanol look there it is ch3 ch2 H s ml alcohols aldehydes ending out so that propane out for example and there&amp;#39;s an aldehyde so CH o at the end ketones ended own so oh and E so that&amp;#39;s propanone for example and so CH 3 Co CH 3 carboxylic acids they ended or Cassatt so for example butanoic acid so ch3 ch2 ch2 ch2 the end in this bit here KU c or h so look out for that that&amp;#39;s the classic sign of carbocylic acid ecology no alkanes and these are things like you&amp;#39;ll come across these and fluro chloro bromo io dough so for example bromo ething is this one here ch3 ch2 BR and the final one of cyclo alkanes so basically just put the word cyclo and front of it and end it in aid so for example cyclo pentene c 5 h 10 so make sure you know these functional groups are really important obviously naming them is going to be crucial you are going to be expected to name these molecules and so make sure you do know them okay so talk about naming and let&amp;#39;s actually look at some so this is nomenclature which is the password for naming molecules and we use the I you pack rules and so I you pack is basically like a governing body but like FIFA for football so basically this is a FIFA for chemistry of PEC sorry so these basically govern the rules and naming molecules and naming the elements of the periodic table and it&amp;#39;s got a very catchy name and I you pack it actually stands for the International Union of pure and applied chemistry yep you can see whether they&amp;#39;ve called it IU pack instead basically and this is the global language of chemistry and they set these rules out and they&amp;#39;re really handy because it allows us to name long molecules so the first thing they have to do is rename or find the length of the stem by counting the longest continuous chain of carbons so the stem name if it&amp;#39;s got one carbon it Smith it it&amp;#39;s to its east of its three it spoke for as beautify Vaz pen and sixes hex and you can go on and on you can keep on going and then you get seven eight nine two etc so basically you need to know the stem name so we start with the stem name so we find the longest continuous chain in this molecule the longest continuous chain is that one there in case that&amp;#39;s four carbons really really important it doesn&amp;#39;t matter even if it looks like a branch looks as though it&amp;#39;s coming off another carbon you just need to find the longest continuous chain your molecule besides that enough if you don&amp;#39;t find that your molecule will not be named right okay so functional groups on the molecule normally tells you the ending of the name we call it the suffix so then basically it also has an O H group this molecule here which means that this one will end in all because we&amp;#39;ve got two after were two or h groups in this one okay so the third thing what you have to do is number the carbon chain so the functional group sits on the lowest possible carbon number now I can name this in two ways I can either name it one two three four or I can do it this way as this is suggesting one two three four and because I&amp;#39;ve named it this way because my functional groups sit on the lowest number fine numbered it from here one two three four these are HS at sit in the fourth carbon now one is obviously lower than four so we named it from or we number it from this way round and then what have to do is make a note of the carbon number to the OHS attached to and place this number before the suffix and this is the type of butan one all and this one here so again we&amp;#39;re going to put obviously one because it&amp;#39;s sitting on the first carbon we put that before the suffix at the end okay so any side chains are side chains and less important functional groups are written as prefixes in alphabetical order okay so this is really important so in this case we obviously have a methyl group load is there we&amp;#39;re going to meet the R group hanging off this third carbon carbon and three and finally if there is more life there are more to say more than one identical functional group or sidechain we put die tri or tetra in front of it so die for to try for three tetra for four so this one here is three me style boot on one one dial okay right but let&amp;#39;s just break this down a little bit we&amp;#39;ve got three nice I&amp;#39;ll we&amp;#39;ve got a methyl group they&amp;#39;re sitting on the third carbon carbon number three butane because you&amp;#39;ve got longest carbon chain is butan and one one because we&amp;#39;ve got two alcohol groups sitting on the carbon number one so we call it one one and die that tells we&amp;#39;ve got two of them all because we&amp;#39;ll see it&amp;#39;s an alcohol so make sure you&amp;#39;ll be able to name that and look for the longest carbon chain okay mechanisms right so a chemical mechanism shows the movement of electrons during a chemical reaction now organic chemistry is all about mechanisms you have to be able to show them to show how reactions occur and the hours are crucial so you need to know about these hours so we use a curly arrow to show the movement of a pair of electrons and you&amp;#39;ll see this throughout the rest of the organic chemistry topic and they always start from an area where there&amp;#39;s lots of electrons could be a double bond or lone pair and in suit on the red arrow they&amp;#39;re basically the end of the arrow is basically showing you where they move where the electrons are moving to and or it could be the formation of a new bond and sometimes it is so and free radical mechanisms and we don&amp;#39;t require any curly hours you&amp;#39;ll see free radicals in the halogen or topic halogen or alkanes topic but we don&amp;#39;t need to know them for this so that makes it a little bit easier and a mechanism showing how an OHA is reaction reacts with bromo ething okay so let&amp;#39;s have a look at this as an example so you can see here that we&amp;#39;ve got a no h- and a bromo ethane molecule basically we&amp;#39;ve got the lone pair now curly I was busy show this bit here look the electrons are moving from a lone pair to a bond or the transform of with the carbon so if you look that&amp;#39;s going from an area where loads of electrons to adults positive carbon ok also this one&amp;#39;s forming a bond here but also the curly ours can show how we can break a bond as well electrons are in this bond but the electrons are now moving onto the bromine here so the arrows are representing the same thing but they always start familiar with electrons you throw a lone pair of a bonds this is showing bond making this is showing bond breaking so it doesn&amp;#39;t really matter and curly ayahs can be used to demonstrate both okay and obviously the final product in this case is just the example is reformed an alcohol here so this is a señal and a bromide iron as well and so yeah and the we did have sodium in here because we&amp;#39;re going to react with sodium and if it was sodium hydroxide but it&amp;#39;s a spectator ion doesn&amp;#39;t actually get involved with the reaction okay so make sure you know mechanisms you&amp;#39;ll see them quite a bit anyway in the organic topic later on which is just showing you kind of an introduction to it okay structural isomers so chain isomerism right you need to know about all these different types of isomers so structural isomers have the same molecular formula but a different structural formula ok so there&amp;#39;s three types here that we need to know is chain positional and functional group ok we&amp;#39;re going to go through each one make sure we know what the are we&amp;#39;ll start with chain first so basically definitions are important here same molecular formula but different arrangement of the carbon skeleton okay so let&amp;#39;s have a look at an example so here&amp;#39;s pentane and an isomer of pentane could be to me sour buting now both these formulas have the same molecular formula and but the arrangement of the atoms as you can see is different so this one has just been shuffled around a little bit but if you count the number of carbons and hydrogens they&amp;#39;ll be the same as what&amp;#39;s in tenting so these are actually isomers of each other chain isomers okay right so let&amp;#39;s have a look at positional isomers so these have the same molecular formulas it&amp;#39;s the same as before but different position of the functional group okay of the carbon skeleton so positional look at the word before the word item a positional is the change of position of the functional group so here&amp;#39;s an example this is pen and one all and the positional eyes from open and what all is pen unto are so the position of the alcohol group has moved is moved from the end to the middle not classic sign of a positional iseman and a functional group isomerism this basic again the same molecular formula of start with the same thing but a different functional group the word in front of the I Smith tells you what&amp;#39;s changing since the functional group is changing so for example his pen twonny and basically we need to have a molecule that doesn&amp;#39;t have an alkene in but has the same molecular formula and that can recently cyclopentane cyclopentane has the same molecular formula it spent money to count the number of carbons and hydrogens and you&amp;#39;ll see that from there you can see crucially there&amp;#39;s no double bond so it&amp;#39;s a definitely a function of your basement okay you also get these types of isomers as well which are stereo isomers or also known as easy isomerism now these are a little bit tricky so stereo isomers stereo isomers have the same structural formula okay but a different arrangement of atoms in space okay so an example is an easy isomer okay that you need to know and you&amp;#39;re skeptical as well but optical think of it is so you find that but you got stereoisomerism so we&amp;#39;ve got a CC double bond okay and all these things do when you&amp;#39;re looking at easy A&amp;#39;s okay so we&amp;#39;re looking for the alkenes and the atoms are bonded directly to this aisle flat their planar okay so the atoms can&amp;#39;t rotate around this bond because it&amp;#39;s rigid it can&amp;#39;t move and this Bend you get some special type of isomerism which we call it stereoisomerism or easy so let&amp;#39;s have a look at these two examples here so these are two stereo isomers of each other they have the same structural formula ch3 ch2 CH ch ch3 but we can&amp;#39;t twist the double bond in order to turn one isomer into the other so if you look at this one there&amp;#39;s three bonds this can&amp;#39;t rotate so you can see this one and this one you can see the main difference is basically the CH 3 on this one is down here where is this one it&amp;#39;s up there so because this can&amp;#39;t twist I can&amp;#39;t flip that one round to match this molecule here because that&amp;#39;s fixed because I can&amp;#39;t do that this molecule is different to this one and that&amp;#39;s what we call an easier iseman so let&amp;#39;s have a look so got these two isomers have restricted rotation around the double bond okay so we get easy isomerism when you have two different atoms or groups of atoms on the same carbon so if we look at these two here there it is look two different ones we&amp;#39;ve got this one and that one these two are clearly different and these two are different to each other so that&amp;#39;s where we get easier Daesan RISM if we have two hydrogens on the same side here hydrogen air hydrogen air we wouldn&amp;#39;t get easier isomerism okay so we look at the two different groups so we can name these molecules as Y or Z and E stands for n Gagan which means opposite and and these are the same groups that are opposite double bonds and we can label them as Zed or soot salmon which means together and these basically the same groups on the same side of the double bond so let&amp;#39;s label these ones so this one is their heads chewing because look the molecules or the the hydrogens or you could use these ones but the hydrogens are on the same side of the double bond that&amp;#39;s both at the bottom so call it as their depend to e but look at the hydrogens here in hydrogens are now opposite the double bonds so we call this one e pen to e and it&amp;#39;s pretty much as simple as that now it gets a little bit trickier when and we have let&amp;#39;s say we have a groups which are the same so in the previous example we had the two hydrogens obviously ones if we don&amp;#39;t have two hydrogens well then all we have to use something called the carnold prelog rules or also known as kip rules and now you&amp;#39;ve got to be really careful with these okay so we use these conning gold prey log rules or CIP rules kibbles and when deciding for nice meteors ed when we have four different groups around the double bond so look at this example here you can see that we&amp;#39;ve got four different groups unlike the previous one we have two hydrogens here now what we&amp;#39;ve got is h @b r ch3 and a ch2ch3 attached from here so all these are different that&amp;#39;s going to be really difficult when we&amp;#39;re using the normal rules so what we do is you label the carbons with a double bond that&amp;#39;s carbon one and car and two you can see that we&amp;#39;ve related than there then what we do is you calculate the atomic number of the first element directly bonded to the CC bond this atom so the aten with the highest atomic number is given a higher priority now remember it&amp;#39;s atomic number not mass number okay so it&amp;#39;s the number protons the proton number of the atomic number so don&amp;#39;t get them mixed up okay so look at these two obviously ch3 has an atomic number of six or the carbon sorry has an atomic number of six because look at the first element and bromine has an atomic number of 35 bromans got a bigger atomic number so it&amp;#39;s given the higher priority so let&amp;#39;s look at the other side so again carbon on the left there and has the higher priority it&amp;#39;s got six and the hydrogen on the bottom there this one here hydrogen has a lower priority it&amp;#39;s got an atomic number of one so the two higher priorities are actually opposite double bond so this is what we&amp;#39;re saying here so the two high priority groups are on carbon 1 and carbon 2 are opposite sides of the double bond you can see they&amp;#39;re opposite double bond there they are so in that case we call this one at e2 bromo 10 - 2 e the e bit tells us that is opposite the double bond ok so it&amp;#39;s pretty pretty straightforward there ok so these are your and make sure you can obviously a sign these and you can use it&amp;#39;s pretty straightforward just remember that this is the proton number not the mass number okay so you may have to check further down the chain though to work out the priorities and so let&amp;#39;s have a look so here on carbon 2 there are two carbons immediately bonded to it you can see here there we go so these will have the same priority normally and so both have an atomic number of six and but if we look at the next up and down the chain there&amp;#39;s another carbon on the e-file group so it&amp;#39;s here there&amp;#39;s the carbon and this has an atomic number of six but just a hydrogen on the methyl group on here which is an atomic number of 1 so basically obviously if we look at these ones this has got the higher priority on this side but look at this one the atomic number is 6 then 6 because we&amp;#39;ve got 2 carbons this one is 6 then 1 so because this goes to 1 this is a lower priority and this one&amp;#39;s a higher priority so just keep looking down the chain and just add the numbers up so the ether group takes priority this one here over the methyl group and so again we&amp;#39;ve got two higher priority groups opposite the double bond so this one becomes an e1 bromo to meet I&amp;#39;ll Butte 1e okay so again look down the carbon chain make sure you know how to do that and just a kind of trick you&amp;#39;ve got to watch out for these isomers and make sure that you have actually drawn an item it&amp;#39;s different sometimes they can get you to draw these isomers and you haven&amp;#39;t just draw one with a different shape so and basically you need to find the longest continuous chain remember said that right at the start and doesn&amp;#39;t matter the shape the shapes irrelevantly we&amp;#39;re just looking at the longest carbon chain so let&amp;#39;s have a look at this one there&amp;#39;s pentane this one is still pentane it looks a little bit different but it is still pentane believe me and so you again look to the longest carbon chain and look at this one z butene and this one is still Zed butte to e okay and there is no difference even though the hydrogens are at the top on this one and them on the bottom here it is still there beauty so don&amp;#39;t be tempted to draw this and call it something else okay to make sure you kind of look at that for them and that&amp;#39;s it that is your kind of quick introduction to organic chemistry it just gives you an overview of the of the intro to organic chemistry topic for AQA again if you would like to and purchase this this PowerPoint you can and you can use it for whatever you want to do if you just click on the link on the description box for the video underneath you&amp;#39;ll be able together there that&amp;#39;s it bye bye

Transcript for:Introduction to Organic Chemistry (AQA Revision Video)

Transcript for:
Introduction to Organic Chemistry (AQA Revision Video)