CuI, CsI, and NaI each adopt a different type of structure. The three different structures are those shown in Figure 12.26. (a) Use ionic radii, Cs+ 1r = 1.81 A 2, Na+ 1r = 1.16 A 2, Cu+ 1r = 0.74 A 2, and, I- 1r = 2.06 A 2, to predict which compound will crystallize with which structure.

Video transcript

Hey everyone, we're told that there are three different types of crystal structures in this case. Seeing sally need sodium chloride and cesium chloride. And were given the following ionic radi and were asked to determine the structure type of lithium bromine, cesium bromide and silver bromide. Now, before we answer this question, let's go ahead and assess our crystal structures. Starting with ours inks all night. When we look at our catalon and are an ion radius, it looks like our an ion radius is much larger. Then our caddy on radius. Next looking at sodium chloride. When we look at these two values, it looks like our an ion radius is somewhat larger. Then our caddy on radius. And lastly looking at cesium chloride. When we look at these two values, it looks like our an ion radius and our caddy on radius are about the same. Now that we've assessed are three different types of crystal structures. Let's go ahead and move on to our question. So first we're asked to determine the structure of lithium bromide. When we look at our ionic ready we can see that lithium has 0.76 PICO meters. While bromine has 196 PICO meters comparing these two, we have a very different ionic radius. So essentially this will be very similar to ours inc Salena died structure. Since we assessed earlier that the an ion radius was much larger than Arkady on radius in our zinc cell night. Next looking at our cesium bromide, we can see that bromine has 196 PICO meters. While cesium has 167 PICO meters. So this is a similar ionic radius. So this is going to have a cesium chloride type structure. And lastly looking at our silver bromide, we can see that our silver has an ionic radius of PICO meters, while browning has an ionic radius of 196 PICO meters. So this is a somewhat different ionic radius, so this will resemble our sodium chloride and these are going to be our final answers Now. I hope that made sense and let us know if you have any questions.