nomenclature.....uuuummmm?

Question

it says to name the following compounds...
H3PO4
Fe(C2H302)3

how in the wolrd do i even begin this THING? im so confused that its not even funny, and all the sites Ive read doesnt explain good enough. Thank you

Answer 1

It's been a while since I studied this stuff formally but I should still know the answers.

Part of the process to figure out how to name the compounds is to classify them. You probably learned this already, but when you have two a compound with non-metals vs. an ionic compound the nomenclature rules are different.

So, the first one H3PO4 is a compound with two non-metals. If we "reverse the charges," that is bring the subscript 3 of the hydrogen up to the superscript side of the PO4, then we get PO4 3- and likewise H +1. You'll just have to remember that PO4 3- is a phosphate ion. The oxide ions which are formed with nonmetals such as P and S will take the "-ate" name for the form with more oxygen atoms bound and "-ite" will have less oxygens. For example, SO4 2- is sulfate and SO3 2- is sulfite. So since you have 3 hydrogens, you'll name this one trihydrogen phosphate.

Another thing that sometimes helps is rewriting the molecular formula so that it is more recognizable. This certainly helps for the iron compound. C2H3O2 is very difficult to recognize as written, but if you draw out a two-carbon chain and place three hydrogens around them, then you are left with two free bonds on the terminal carbon. Let's put a double bonded oxygen there. Now we have one O atom left, which we can put on the H of that same carbon atom to form a hydroxide ion. After organic chemistry this will all make more sense. Perhaps now you will recognize this as an acetate ion (CH2COOH -). If we reverse the charges as above, we see that this is a Fe +3 ion. So the way we name this molecule is Fe (III) acetate. An old-fashioned naming system may call this ferric acetate. Ferric is used for +3 and ferrous would be used for +2 but this terminology is rarely used nowadays.

Answer 2

H3PO4 is phosphoric acid. PO4(-3) is phosphate (combined with 3H will give you phosphoric acid)

Fe(C2H3O2)3 is Iron (III) Acetate

C2H3O2(-) is acetate, because you need 3 of them, then the iron will be Iron(3). so Iron(III) acetate.