OB: Transitional Metals become ions
too. The rules for ionic bonding
and naming ionic compounds
from the middle of the table.
You must have a reference table
out now, open to the periodic
table.
Let’s look quickly at these basic groupings of metals and non metals:
Group 1 all make only +1 cations, because all have 1 electron in the outer orbital
Group 2 all make +2 cations, because they all lose 2 electrons from their outer orbital
Al makes a +3 cation, because it would lose 3 electrons when it forms a cation
Group 17 all make -1 anions, because all need to gain 1 electron to become isoelectric
to the noble gases.
Group 16 all make -2 anions, they need to gain 2 electrons to fill their outer orbital
Group 15 atoms become -3 anions (you probably know why)
We are about to start discussing what we do with those selected oxidation states.
These numbers will be important for a variety of reasons. With the transitional
metals, the selected oxidations indicate the charge of the cation that they form.
Scandium makes a +3 cation. See that +3 in the corner? That’s what it’s for.
Yttrium too, a +3 cation. Peek at zinc, it only makes a +2 cation.
The transitional metals make the cations that are
indicated, they do not always follow an “isoelectric” rule,
like metals we’ve seen in groups 1 and 2 and Al.
When the transitional metals form cations and bond to anions they make ionic
compounds. Naming these compounds works the same way as the ones you have
already met. For example:
React these atoms by changing them to ions, write formulas and names…
Sc + Cl
Sc+3 + Cl-1
That stuff is called scandium chloride. Try these 2:
Zr + P
In + F
ScCl3
That stuff is zirconium phosphide
Zr + P
Zr+4 + P-3
Zr3P4
In + F
In+3 + F-1
InF3
This is indium fluoride
Titanium has 3 different positive
selected oxidation states.
What is possible here?
Turns out that many of the
transitional metals, titanium
included, can make more than
one stable cation.
Titanium can be Ti+2, Ti+3, or Ti+4
How cool is that?
47.88
Ti
22
2-8-10-2
+2
+3
+4
Let’s look at each of these atoms and list what cations that they make:
V-23
Cr-24
Fe-26
Cu-29
Ga-31
Cd-48
Nb-41
Hg-80
for example: V+2, V+3, V+4, and V+5
Let’s look at each of these atoms and determine what cations that they make:
V-23
V+2, V+3, V+4, and V+5
Cr-24
Cr+2, Cr+3, and Cr+6
Fe-26
Fe+2 and Fe+3
Cu-29
Cu+1 and Cu+2
Ga-31
Ga+3
Cd-48
Cd+2
Nb-41
Nb+3 and Nb+5
Hg-80
Hg+1 and Hg+2
They make the cations that
they do, the reason is that
some of these atoms can
flex and become stable
cations even if the
electrons are not
isoelectric to a noble gas.
They just can.
Just Look.
Let’s make some ionic compounds now.
Combine gold with chlorine (do both cations, one at a time) Write the formulas
Au + Cl
Au+1 + Cl-1
__________
Au + Cl
Au+3 + Cl-1
__________
The formulas are not too tough, but what
will we call these compounds? They can’t
have the same name if they’re different!
Let’s make some ionic compounds now.
Combine gold with chlorine (do both cations, one at a time)
Au + Cl
Au+1 + Cl-1
AuCl
gold (I) chloride
Au + Cl Au+3 + Cl-1
AuCl3
gold (III) chloride
It’s going to take some Roman Numerals
to have these names different. The Roman
Numeral matches the cation charge.
These are called stock names.
Combine every type of manganese cation
with bromine. Write formulas and stock
names for each one. (fill in ion charges)
Mn + Br
Mn + Br
Mn + Br
Mn + Br
Combine every type of manganese cation with bromine.
Write formulas and stock names for each one.
(fill in ion charges)
Mn+2 + Br-1 MnBr2
manganese (II) bromide
Mn+3 + Br-1 MnBr3
manganese (III) bromide
Mn+4 + Br-1 MnBr4
manganese (IV) bromide
Mn+7 + Br-1 MnBr7
manganese (VII) bromide
There are 2 kinds of copper oxide, we saw them both
in the chemical and physical changes lab. One was a
black powder, one was red. Show the two ways copper
and oxygen can combine ionically, write the proper
formulas with their stock names.
Cu + O
Cu + O
There are 2 kinds of copper oxide, we saw them both in the chemical and
physical changes lab. One was a black powder, one was red. Show the
two ways copper and oxygen can combine ionically, write the proper
formulas with their stock names.
Cu+1 + O-2
+2
Cu
+
-2
O
Cu2O
CuO
Copper (I) oxide
Copper (II) oxide
Do Not Forget: the roman numeral matches the cation charge!
Last one…
Combine
tantalum (Ta-73) + sulfur (S-16)
Ta + S
Last one…
Combine
tantalum (Ta-73) + sulfur (S-16)
Ta+5 + S-2
Ta2S5
tantalum sulfide
No roman numeral needed, because
tantalum only makes one cation
(like with sodium, we don’t eat any
sodium (I) chloride, do we?)
At this point, you should be finished up with the
monoatomic ions handout.
You should check your grades, make up back work.
Electrons Lab is due by Friday.
Next Tuesday (in six days) we’ll be celebrating this,
so,
Read the Naming Compounds Diary, do the 4 drills.
Let’s do some drills now.