Draw the structure of the following complexes. What are the oxidation state, coordination number, and coordination geometry of the metal in each?

(a) Na[Au(CN)2]

Video transcript

Hi, everybody. Here's our next problem sketch the structure of K and then in brackets see you and in parenthesis 02. So we have potassium and then a complex of copper with 20 ligands identify the co ordination geometry, oxidation number and co-ordination number of copper. So we need to think about, we need to find our oxidation state of copper and think about how this complex is arranged. Well, the easiest one here is co-ordination number. We just need to look at how many bonds there are to our copper atom. We have a very simple ligand hydroxide O minus and there's just two of them. So we only have a co ordination number of two and a co-ordination number of two has just one basic arrangement. So it's co-ordination geometry will be linear. So that's pretty straightforward. Now, we just need to get to our oxidation number of copper and then we'll make a little sketch of the structure. Well, we have a counter ion here, we have potassium which is a group one, a metal, we'll expect to be K plus with a positive one charge. Now, we need to look at our, our complex here, our copper complex, we see, we know that if our potassium counter ion has a charge of positive one, our overall charge for a ligand must be negative one. So the overall charge of negative one must equal the oxidation state of copper o period S period of copper plus the charge on our ligand, which is negative one and there's two of them. So multiplied by two. So negative one equals oxidation state of copper plus negative one multiplied by two. So it's solved for the oxidation state of copper that will equal negative one plus two. So it's going to be positive one. So we can add that to our answers oxidation number is positive. One last thing we need to do is sketch the structure. We've got a linear geometry. So quite straightforward, we have copper in the middle, there's RCU and then a bond to an oh on either side with oxygen doing the bonding here. And then we put brackets around this whole structure since it's an ion with a charge of negative one. And then we have our potassium ion over here on the left as K plus or rather, we can just leave that as a single ne single minus sign as our charge for our ion. So we now have our structure of K plus and then our copper bound with an hydroxide ion on either side and a negative charge on that ion there. So there we go, we have our co-ordination number of two linear geometry, oxidation number of positive one and our structure see you in the next video.