Consider the ionic compounds KF, NaCl, NaBr, and LiCl. (a) Use ionic radii (Figure 7.8) to estimate the cation–anion distance for each compound.

Video transcript

Hey everyone in this example, we need to calculate the cat ion ion distance for the given compounds magnesium, sulfide, calcium oxide, and strontium oxide. We're told that the ionic rate eye of some elements are given below here. So to find our caddy on ion distance for our given compounds, we want to recall that we're going to take our caddy on radius of our Catalan and the molecule and add that to our an ion radius. So beginning with our magnesium sulfide, We would recognize that Magnesium because it's in group two a will form the MG two plus cat ion. And we would see that that has the Catalan radius of 86 m. And because sulfur is in Group six A. Of our periodic table, we would recall that atoms in group six A form the two minus an ion. So we would form S two minus. And we would recall that according to the chart here, it has the ionic radius of 1 70. So we're going to take 86 PK meters and add that to the radius of the S two minus an ion which is 1 70 PICO meters. And what we'll get as a total is a value of 256 m. As our first answer for the caddy on ion distance of magnesium sulfide. Moving forward with our second compound, we have calcium oxide, we should recognize that calcium is in Group two A and therefore forms the C. A two plus caddy on which according to the chart we see correspond to the ionic radius 114. So we have 114 kilometers from Arkady on here and then oxygen we want to recognize is also in Group six A. And forms the oh two minus an ion. And as we can see in our chart we have an ionic radius of 1 26.2 m for our oxygen and ion. So adding these two values up gives us a total of 240 PICO meters as Arkady an ion radius for calcium oxide. And lastly, we have our last compound which is given as strontium oxide. We would recognize that strong TM is located in group two a. of our periodic tables. And we recall that atoms in Group two A. For the last time will form the two plus Catalan. So we have S. R. Two plus. Looking at our chart above, we recognize that the strontium two plus Catalan has an ionic radius of 132 PK meters. And looking at our oxygen atom here, we again recall that it will form the 02 minus an ion because it's in group six A. And looking at our chart, the 02 minus an ion has an ionic radius of 126 PK meters. So we will add 126 PK meters again. And this total here will give us a value of 258 m as our cat ion ion radius for hours, john team oxide compound. So everything boxed in blue represents our final answers for our cat ion ion radius for our given compounds. I hope that everything I explained is clear. If you have any questions, please leave them down below and I will see everyone in the next practice video.