2.2 Naming Ionic Compounds Flashcards
Whats an ionic compound?
Metal and non metal
NaCl
Polyatomic ion = one portion is covalently bonded
Binary molecular compounds
* covalently bonded 2 (bi) compounds
* These are both nonmetals
typically we only name acids after they’re dissolved in water and are aq
Acids - I think these always start w/ H
Binary acids - typically just 1 other element
* HCl (so the acid is H w/ 1 other element)
* This is a combination of 2 non metals (H is not considered a metal)
Oxyacids - an inorganic acid whose molecules contain oxygen
* Oxyanions associated w/ it
* H2SO4
* so the polyatomic is an oxyanion (has oxygen and is negatively charged) - even though this is still covalently bonded
Naming Ionic compound
NaCl = Sodium Chloride
Name the cation first (metal)
Name the anion second (non metal)
For the anion we add the ide ending
* so chlorine turns into chloride
Group 7 atoms typically have a negative 1 charge. This is because they fill their valence shell to 8 (octet rule) from 7, which means gaining 1 electron
For isntance its Cl-
They want as many electrons as the nearest noble gas
metals on the other hand want to lose electrons to drop their valence electrons down to the lower 1
* thats why metals get +1 and +2 charges in the first 2 groups
however, transition metals are harder to predict
* these can take on multiple charges
Ionic compounds should have no overall charge
CuCl
Well Cu can take on multiple charges however, Cl is always -1, meaning we can predict Cu because ionic compounds always neutralize
Cu = +1, Cl = -1 = CuCl
Copper(I)Cloride
* added ide
CuCl2
Well now we know the two Cl-‘s have bound to a Cu meaning the Cu must have a +2 charge. Now since Cu is a transition metal that means it can take on multiple charges, meaning we can’t just name it Copper Chloride. We need to be able to dilinaite it from other ionic compounds that could carry different charges but be named the same way
Put a roman numeral w/ the charge of the cation in the roman numbers
Copper (II) Chloride is the correct name for this
* I think I pretty much always do this for transition metals
can’t just name these two the exact same way
Ag (silver) is a transition metal. However, unlike most of the others it always has the same charge. What is it?
+1
Makes sense its 2 groups the left of the +3 charges. Can look at a periodic table
Zn and Cd are transition metals, however, unlike the others they always carry the same charge. What is it?
+2
makes sense, they’re 1 to the left of the +3 charges
Al always carries the same charge (I think its considered a transition metal) What is it?
+3
makes sense its one to the left of carbons row which is +4
So for Ag+1, Cd+2, Zn+2, Al+3 since these are stable transition metals that dont ever have different charges we dont add roman numerals into their ionic compound name.
most of the transition metals have 2 primary charges they carry
Oxidation state = how many electrons they have
* higher oxidation state = lost more electrons (more positive)
* lower oxidation state = atom has gained more electrons (more negative)
Copper(I) Chloride
* For the lower oxidation state (in this case the transition metal is +1 - use the term Cuprous Chloride
* add the ous suffix
Copper(II) Chloride
* add the suffix ic
* Cupric chloride
NH4Br
This is all nonmetal, however it has an ammonium cation in it
NH4-
Br+
Ammonium bromide
CuSO4
name this
SO4^2- = anion
means Cu must have a -2 charge
* cation
Copper(II)Sulfate
The reason we need to roman numberal 2 when sulfate always has a -2 charge charge
* If the compound were Cu2SO4 the copper would be +1 and the name would be Copper (I) sulfate. Since we dont use number prefixes we need the charge # to know how many atoms of copper were dealing with.
RULE: if you’re naming a compound w/ a polyatomic ion in it - you can automatically know its an ionic compound
So we dont pick di even though theres two of them. We don’t have to state how many there are because it will be known dpending on the charge on S
no roman numerals because neither of them are transition metals and dont have charges that change
So the trick here is knowing that you don’t change the suffix of the polyatomic ion when it comes second. So you wouldnt add ide
magnesium sulfite
key is knowing that theres -6 on oxygen. since theres 2Fe each one must have +3 to even it out.
TiO2
Makes sense.
* Ti = 4+ charge (found from roman numeral)
* O = -2, however there must be 2 oxygens to fully balance the ionic compound and make it neutral
Na = Na+
Dichromate = polyatomic ion
* Cr^2O7^2-
