Leia here from leers side.com and in this video I will show you how to name alkal halides but what is an alkal halide an alkal halide or Halo alane comes from the word alkal meaning a carbon chain and halide meaning a hogen hogen refers to group seven on the periodic table typically shown as X and represents the atoms Florine chlorine Romine and iodine the rules for naming alkal halides are just like the rules for naming organic compounds where the hogen folds into the prefix category or substituent to name a hogen in an organic compound you drop the I from the ending and add the letter O for example for Florine you drop the in add the letter O and you get floro for chlorine you get chloro for Bromine you get bromo and for iodine you get ioto let's start with this simple example we start by identifying and highlighting the parent chain and the numbering from the side that gives you the lowest number for the hogen in this case we number from the right for a total of four carbons which gives me a first name of but only single bonds gives me a last name of a and a hogen substituent gives me the prefix of two bromo putting the name together I get two bromo butane now let's look at an example where you have multiple halogens first I identify and highlight my parent chain I can choose to number from the right or the left given that both hens show up in the middle I have a total of three carbons for a first name of prop only single bonds gives me a last name of a the fact that I have two chlorine atoms showing up on carbon number two I have to write 2 comma 2 to show which carbon both halogens show up at and then I have to put the prefix die before chloro again to signify that I have two chlorine atoms putting the name together I get 22 D chloropropane when you have a hogen and a carbon substituent they have equal priority and so you number in a way that gives you the total lowest set of numbers that means both of these examples are numbered from the left so that for the first one I have a two bromo and three methyl but for the second one I have a two methyl three bromo the parent chain for both of these examples have a total of five carbons and only single bonds giving me a first name of pent and the last name of a in the first example I have bromine on Carbon 2 giving me two bromo and methyl on carbon 3 giving me three methyl for the second one I have methyl on Carbon 2 for two methyl and bromine on carbon three for three bromo putting the name together the prefixes are arranged in alphabetical order regardless of their number since B comes before M bromine is going to be named first that means the first molecule will be two bromo 3 methyl pentane and the second molecule will be three bromo to methyl pentane but what happens when you have both a carbon and a hogen at the same position in this molecule I can number from the left getting two methyl or number from the right to get two ioto in this case you take alphabetical order into account since I comes before M we start numbering from the right so that ioto will come before methyl since I have a total of six carbons in my parent chain I have a first name of hex having only single bonds gives me a iodine having the higher alphabetical priority gives me two ioto methyl having the lower alphabe I priority gives me five methyl for a final name of two ioto five methyl hexane now let's look at this example we have a substituted cyclohexane so we start numbering from the hogen and go clockwise or counterclockwise since we have no other substituents six carbons gives me a first name of hex the rink gives me a prefix of CYO and only single bonds gives me a last name of a Florine occurs on carbon one so we would put one floro however since Florine is the only substituent the number one will be self-understood and does not have to be included therefore instead of one fuyoh xane I skip the one and simply call this molecule floc cyclohexane let's try a multi substituted cyclohexane I start with my parent chain of six carbons for a first name of hex only single bonds for a last name of a and a ring for a prefix of cycl when it comes to numbering since I have two halogens on one carbon and one hogen on a second carbon I start numbering from the carbon that has more things or more substituents coming off of it I have the option of going clockwise or counterclockwise however if I go counterclockwise my second hogen gets a number five but going clockwise my second hogen gets a three and so I have to go clockwise since I have multiple halogens the number one cannot be assumed and so I have to put the number for each two chlorines on carbon 1 gives me a 1 comma 1 Doro one iodine on carbon 3 gives me three ioto when putting the name together we alphabetize based on the hogen not based on the word D since C comes before I we have 1 one Doro 3 ioto cyclohexane when a pie Bond and a hogen compete for priority the pie bond is going to get the lower number in this case I highlight my parent chain and start numbering from the left since the double bond is higher priority than the chlorine I have four carbons for first name of but a pi Bond starting at Carbon one for a last name of one in since chlorine occurs at Carbon 4 we have 4- chloro for a final name of for chloro 1 butine are you struggling with Organic Chemistry are you looking for information to guide you through the course and help you succeed if so download my ebook 10 secrets to acing organic chemistry using the link below or visit leers side.com orgo secrets that's o rgo secrets for information regarding in online tutoring visit lei.com orgor that's o RG tutor if you enjoyed this video please give it a thumbs up and even share it with a friend or two if you have any questions regarding this video leave a comment below or contact me through my Facebook page at facebook.com/ forai there will be many related videos posted over the course of the semester so go ahead and click click the Subscribe button to 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