Identify the following pairs of complexes as coordination, linkage or geometric isomers. For the first one, look for where the difference is. The difference is here and here. In the first one we have no two where the nitrogen is connecting directly to the cobalt metal cation, but then next to it it's the oxygen within the nitrite ion that's connecting to the metal cation. How is this possible? Through resonance? So we'd say the first one is a linkage pair or a pair of linkage isomers.

For the next one, look to see where is the change. Where is the difference here? Well, in both they're connected to Nichols, connected to two waters and it's connected to to ammonia. But as we can see in the first one, the waters are on the same side, the ammonias are on the same side, but the iceberg next to it, they're opposite of each other now. So this would be a geometric pair of isomers.

So next let's see. Next we have what? What's the difference? Well, the chlorines here are next to each other, making them cysts, and now they're opposites of each other, making them trans to each other. Also remember in this first example, if we look the formulas are what MX₂Y₂ and these two are MX₂Y₄. Those tell us that these are geometric isomers as well.

Then finally the last one. What's the difference between these two? Well it looks like we have a branch here and a CL here and it looks like they swaed places. We substituted out the counter ion and the basically anionic ligand here. This is an example of coordination isomers, so that's what we can say about each of the following pairs given to us within this example problem.