Assign a systematic name to each of the following ions.

(c) [Fe(H₂O)₅NCS]²⁺

(d) [Cr(NH₃)₂(C₂O₄)₂]^-

Video transcript

All right. Hi, everyone. So this question is asking us what are the systematic names for the part one A un 05 CN two positive and part two M OS 042 en 22 negative ions. Here we have four different answer choices, proposing different names for both complex ions. So like I mentioned previously, right, both compounds mentioned here happened to be complex ions. Each of which are composed of a metal cion in the center as well as ions or molecules attaching to the central metal atom or cation referred to as lith. So starting off with the first compound that's A U no five, the N two positive. The first thing I like to do is always name all ligands in alphabetical order. In this case, it appears that we have two different types of leggings, one of which is no and the other is CN. Now recall it an O or the no ligand is referred to as nitro zole. Whereas CN if you recall actually has a charge of negative one, which gives it the name cyanide. Now because the nitros ligand is neutral, its name is not going to change. However, cyanide is an anion, which means that the suffix ID E gets dropped completely and replaced with an O giving the name Cyano. So both of these ligands happen to be mono dentate, meaning there's only one point of attachment to the central atom, which means that they're going to use the same set of prefixes to indicate the quantity of each one in the complex itself. Now, because there is only one Cyano lien present in this complex, there's no need to put a prefix in front of it. However, because there happened to be five Nitros liens. The prefix before is PTA. So here when arranging the names of the lids in alphabetical order, you do. So depending on the name of the legend and not its prefix, right? So because the sea in Cyano goes before the end in Nitro Zole, the name so far become Ciano Hunter Nitros. And now our next step is to go ahead and name the central metal. Now, the symbol A U indicates that the name is gold, right? So after all ligands have been listed in alphabetical order, goes the name of the metal with no spaces in between. So, so far I have Cyano Penta Nitro Zole gold. However, because gold is a transition metal, there has to be a Roman numeral in parentheses, specifying its oxidation state. So here recall that the charge of the complex is the total oxidation number of the complex itself and the sum total of the oxidation states of the metal as well as all ligands must equal the total oxidation number, right. So if the oxidation number of gold is X, then X added to the oxidation number of the nitro Zoe groups, as well as the oxidation number, oxidation state of the cyano against must equal positive two. So and so the oxidation states must also be multiplied by their quantity in the complex. Now, the Nizol ligands happen to be neutral with an oxidation state of zero, right? So because of this zero, multiplied by five is going to be zero, which means that the term in my equation here, further nitro or ligands gets essentially canceled out. And so cyano or the cyano ligand because it has a charge of negative one, it's going to have an oxidation state of negative one. So XM subtracted by one equals positive two. This means that X is equal to positive three, which means that the oxidation state of gold is positive three. So in parentheses, after the middle name should go a Roman numeral three like. So this results in a name of Cyano Penta Nitros gold three or the first ion. So now we can proceed with the second one. So for part two, we have mo so 42 en two too negative. So starting off with our ligands, we have two different types and the first of which is so four, which if you recall corresponds to the sulfate ion. So here for now, I am going to write sulfate and my second type is abbreviated as en but recall that the abbreviation en stands for Ethylene Diamine. Now recall that sulfate is an anionic ligand, which means that the suffix is going to be replaced with an O at the end. So the E at the end of the name sulfate gets dropped completely and replaced with an O resulting in the name Sol fo. And since this is a Monod deny ligand, because there are two sulf fatal ligands present in this compound, the appropriate prefix is dye to indicate their quantity. Now recall that ethylene diamine is actually a poly dentate ligand and there's already a prefixed dye within the name. So because of this, to indicate the fact that there are two ethylene diamine ligands present in this complex, the prefix is going to be bis and the name ethylene diamine gets enclosed in parentheses. Next is the name of the central metal which happens to be mo lived in them. However, recall that the complex for part two happens to be negatively charged overall. So because of this, right, the the final part of the name molybdenum in this case, enum gets dropped entirely and replaced with a te resulting in the name moli date. So now we have to find the oxidation state of molybdenum in this complex. So in this case, X is the oxidation state of molybdenum. And so I'm going to set up a similar equation where I take into account the oxidation states of all ligands as well as their quantities to equal the overall charge, which is negative too. Now recall that ethylene diamine is neutral, which means that its oxidation state is going to be zero. Whereas for the sulfate ligands, it is going to be negative too. So negative two multiplied by two means that my equation simplifies to X subtracted by four added to zero equals negative two. And so when I add both sides by four, X is equal to positive two, which means that after the name Moli date should go a Roman numeral too in parentheses. So once again, when combining everything together, the names of legends must be arranged in alphabetical order. So because the e in Ethylene Diamine goes before the s in sulfate, my name becomes Biss Ethylene Diamine die. So fatal Mo Lip Date two and there you have it. So if I scroll up here to see the answer choices once more or in will be option B in the multiple choice. The systematic name for the first ion is cyano P and Nitros or gold three. And for the second ion it is bis ethylene Diamine Diulo moli two. So with that being said, thank you so very much for watching if you stuck around to the end. And I hope we found this helpful