In the ionic compounds LiF, NaCl, KBr, and RbI, the measured cation–anion distances are 201 pm (Li–F), 282 pm (Na–Cl), 330 pm (K–Br), and 367 pm (Rb–I), respectively. (c) What estimates of the cation– anion distance would you obtain for these four compounds using neutral atom bonding atomic radii? Are these estimates as accurate as the estimates using ionic radii?

Video transcript

Hey everyone in this example, we're told that the caddy on an ion distance in potassium bromide is experimentally determined to be 330 m were told that the atomic radius and ionic radius is are given below and we need to determine which is the more accurate estimation of the ionic carry on an ion distances. Either the atomic radius or the ionic radius. So what we're going to do is use the information given to us for atomic radius for each autumn and ionic radius for each atom. And what we would say is that For potassium we have the atomic radius of 203 PK m. And we're going to add this to the atomic radius of bro. Mean giving us 120 km since we know that in potassium bromide, these atoms are bonded to another. When we add these two atomic radius values up, we get a value or a total of 323 PICO meters. Looking at our ionic radius values for an ion of potassium, we have a potassium Catalan with the ionic radius of 152 PK meters. And because this ion is bonded with bromine in the compound potassium bromide, we're going to add this to the ionic radius of the bromide, an ion which has the radius of 182 PK meters And this is going to give us a total of 334 PICO meters. So we can say that because 334 is close to 330 PK meters, which is the experimentally determined caddy on an ion distance for potassium bromide, we would say that therefore, ionic radius is the most accurate estimation of the ionic caddy on an ion distances. And so this would be our final answer to complete this example. So I hope that everything I explained was clear. If you have any questions, please leave them down below. Otherwise, I will see everyone in the next practice video.