Howdy everyone! Mr. Causey here with another problem of the week
and this week we're going to look at ionic compounds and how to name them.
So let's get started. How would you name the following compounds?
And we have six
ionic compounds. And I know they're ionic because it's a metal
and non-metal so that makes them all ionic
and the thing we need to remember about ionic compounds
is it's a metal and a non-metal. So let's get out our periodic table
and take a look at the periodic table here. If you'll look at Boron,
Silicon, Germanium, Arsenic,
Antimony, Tellurium, Polonium, and
Astatine, these are the
semi-metals or metalloids and they kind of separate the non-metals from the
metals. To the left of them you are more metallic
and to the right of them you are less metallic so you've got to get out your
periodic table
and you have to use it. It's one of your most important tools, people.
You also might want to download this handout
right here that I have at yourchemcoach.com.
Go down to the URL at the bottom of the page, just put that into your browser,
go and download this handout. It's on roots and prefixes,
it has the most common polyatomic ions on it as well.
It's a great sheet to have and boy I'll tell you if you can talk your teacher into letting you use that
or at least use it as a way to memorize all this information,
it's a great tool. One of the first things you want to do is write the name of
the cation
and that's usually the first element
and it's the metal. Then you take the root of the
anion and add -ide.
Just like Oxygen, the root is "Ox" so add "ide" and you have
oxide. Then 3, check the charges of the metals.
You always want to make sure you check the charges and everything's going to balance out
especially those metals that have multiple ions.
They have multiple charges like Chromium,
you have Chromium plus one and you have Chromium plus three and Chromium plus six!
And so you have to know which ion you're talking about
and balance it and also it's where we use our
Roman numerals. And use your Polyatomic ion sheet.
Now the way we name these ionic compounds is different than the way we
name a covalent compound. It takes a little more thinking
because you have to be sure whether or not you're going to be using a Roman numeral
or one of the old names. Now I say you should learn the new system
but should be aware of the old system. It's on the handout if you download it,
those who have the old system names.
Alright, let's keep going. To the magic blackboard!
Sodium Chloride! Well first of all, it's Sodium
and notice that you have a Chlorine ion.
And by the way Sodium is plus one and chlorine is negative one
and if you don't know how to do charges you need to go and find my
video on valence electrons and lewis dot symbols and the one on oxidation
numbers
and learn about how to figure out the charges.
Sodium is plus one, Chlorine is negative one, it balances so we have Sodium
Chloride and you notice we add the -ide.
Pretty simple and straightforward. So let's look at the next one.
Cs I. Cesium and we have
the "I" which is Iodide. Pretty straightforward
and both charges, Cesium is a plus one and Iodide is negative one
so they balance out and we're good. Calcium
Carbide. Well we have Calcium and Calcium has a plus two charge. SO you notice that we
have
two Carbons there. That's good but Calcium does not have more than one
ion so we don't need to use Roman numerals, just
write down Carbide. And remember, don't use numerical prefixes with ionic
compounds,
that's reserved for molecular or covalent compounds.
BaCO3, Barium and CO3 is a polyatomic ion so I look at my chart
there
and it's carbonate. Barium carbonate. You need to
be aware of and recognize polyatomic ions.
CaO, Calcium Oxide.
Calcium is a plus two, Oxygen's a minus two so it balances out real nice and
there are no worries about the ions. Calcium has one type of ion.
Copper and Chlorine, now apparently
there are two Cl's there. There are two Chlorines
so most people would say Copper Chloride
but that's not correct. And the reason that's not correct
is because that's Copper(II)
and I know it's Copper(II) by the Chlorine. Notice the Chlorine right here
has two ions and Chlorine is a negative charge.
That's a negative two over here, that means this is plus two because they have to
balance
and Copper can be Copper(I) or Copper(II)
and in this case it's Copper(II) because of the charges. So then I would write Copper(II)
Chloride
and that's how we do it. Send an email to mrcausey@mrcausey.com
and check out mrcauseysworld.com. There are videos and PowerPoints and much much
much more.
Also, subscribe to my YouTube! Yeah!
Studies have shown that it increases your IQ.