Naming Ionic Compounds with Transition Metals Introduction

this is an

introduction

to

naming

ionic

compounds

with

transition

metals

the

transition

metals

are the elements in this part of the periodic table and when we write the name for an

ionic

compound that contains

transition

metals

those names usually have Roman numerals in the middle of them so in this video we'll learn how to take the formula for a compound that contains a

transition

metal and how to write the name for it with Roman numerals and everything so

transition

metals

the

transition

metals

are the elements in this part of the periodic table here and I've written in some of the most common I'm also going to be talking about some of the

metals

over here which aren't technically

transition

metals

but they act a lot like them these

metals

are unique because many of them are able to make multiple ions with different charges so iron Fe for example is able to make an Fe 2 plus ion but it's also able to make an Fe 3 plus ion okay this is different for the

metals

say

over here that tend to always make ions with the same charge sodium for example is in this +1 column here and so when sodium isn't in an

ionic

compound it always makes an ion with a 1 plus charge magnesium here is in this 2 plus column so when it is in an

ionic

compound it makes a 2 plus ion but the

transition

metals

can make a wide variety of different ions with different charges some of them can even make 4 or 5 different ions each with a different charge so these different charges on

transition

metals

really come into play when we want to name a compound that contains a

transition

al so here we have fecl3 and for the FE the iron we can't tell right away just by looking at this whether the Fe is Fe 2 plus or whether it's fe 3 plus right we have these two different types of ions that Fe can make now we can distinguish between these two ions by using Roman numerals to give them different names so the fe 2 plus ion we call that iron 2 with the Roman numeral for 2 in

parentheses the fe 3 plus ion we call that iron 3 with a Roman numeral for 3 in parentheses and we'll use these ion names when we want name the whole compound so if the FE here turns out to be Fe 2 plus we'll call this compound iron 2 chloride and if this iron is iron 3 plus we will call the compound iron 3 chloride so in order to figure out whether we're talking about iron 2 chloride or iron 3 chloride here we got to do a little bit of math and work backwards to figure out which of

these two charges iron has in this particular compound let me show you how to do it so to find the charge of a

transition

metal we start by focusing on the ion with a charge that we do know that certain that's not going to change and for this that's going to be CL CL is in this column here on the periodic table so we know that in an

ionic

compound CL always makes an ion with a 1 minus charge okay so we've got CL 1 minus now how much total negative charge do we have here we have 3 CL

s so that's going to be 1 2 3 and since we have 3 of them the total amount of negative charge is going to be 3 minus now in an

ionic

compound the negative charge always has to balance out with a positive charge so if we have 3 minus on this side we've got to have 3 plus on this side so what's the charge on iron well there is one iron ion in this compound which means that all of the positive charge has to be on this one island which means that its charge is Fe three-plus okay so one

ion of fe 3 plus gives us three plus of charge which has to be balanced out by the three - over here which is distributed over the 3 CL minuses so that's how we figure out the charge on I and since this is iron three-plus the name for this compound is going to be iron 3 and then 4 CL when CL when chlorine becomes a negative ion we call it chloride the IDE usually gets added to the name of an element when it becomes a negative ion so chloride is what we call CL one - so iron 3 chloride is the

name of this compound we had to work backwards and figure out the charge of iron and then we can call it iron 3 so if you want to get really good at

naming

compounds

with

transition

metals

and using the Roman numerals and all that you just got to get a lot of practice so I've made another video that's just a whole bunch of practice problems on

naming

ionic

compounds

with

transition

metals

but before you check that out I want to talk about a couple of important things the first thing I

want to talk about is when we use Roman numerals for

naming

and when we don't this confuses a lot of students ok so when do we use Roman numerals well we use Roman numerals when we're

naming

compounds

that contain

transition

metals

so here are 3

compounds

that contain

transition

metals

and as you can see we use these Roman numerals and we use the Roman numerals because copper iron and vanadium are

transition

metals

which means that they can make multiple ions with different charges so we

kind of need to pin down the specific ion that we're talking about in each one of these

compounds

right so we put this one here to say we're talking about copper 1 plus because copper could make other ions we're talking about iron 3 plus here we're talking about vanadium 4 plus because they could be a variety of different ions now on the other hand we don't use Roman numerals when we're

naming

compound that don't contain

transition

metals

that contain for example the

metals

over here take potassium iodide for example potassium K is in this column it's in the one plus column which means that in an

ionic

compound potassium always makes an ion with a 1 plus charge that's the only choice it can only be one plus so we don't need to put a Roman numeral in there to specify that it's 1 plus because that's the only choice that it could be calcium nitride over here calcium is in this 2 plus column and it can only make an ion with a two plus charge

in an

ionic

compound so again we don't need a Roman numeral to say that because there's only one choice and that's 2 Plus now aluminium over here could only make a 3 plus ion so you don't need to use Roman numerals with aluminum either and I should point out that some of these

metals

here that are not technically

transition

metals

still can make ions with different charges so we have to use Roman numerals when we name

compounds

with tin and lead in them as well but here's a

big point if you're

naming

compounds

with ions that can make different charges you always need the Roman numerals but don't put those Roman numerals in if you're

naming

compounds

with

metals

that can only make one charge not only is a waste of time to put those Roman numerals in but it's wrong you just shouldn't put them in there now we have to use this method of working backwards in order to name

compounds

that contain most

transition

metals

and we also have to use this

method to name

compounds

that contain

metals

like tin or lead that are able to make more than one type of ion but there are two important exceptions and I need to tell you about these are silver AG and zinc Xion even though these two elements are

transition

metals

they're only able to make one type of ion so silver AG always makes a g1 plus it's always one plus and only one plus Zink Xion always makes an ion that is Z n 2 plus now that means that when we name compound to contain silver

or zinc we don't have to use Roman numerals because we're only talking about one type of ion okay so a compound like this agcl you don't have to do any math at all you don't have to use a working backwards approach you just call it silver chloride ZN CL here super easy we just call that zinc chloride and since these elements always make ions with just one charge we don't have to use the Roman numerals when we're

naming

so it would be wrong to call this silver one chloride

or zinc 2 chloride here there's only one possible ion so we don't use the Roman numerals we only use the Roman numerals if we're trying to distinguish between multiple types of ions with different charges so that's an

introduction

to how we name

compounds

that have

transition

metals

and in the next video we'll do a whole bunch of practice problems so you can really get the hang of it this is one of the things that you just get better and better at with more practice so check

out that video you'll get super good at it really fast