Question

question 6 2 pts on the basis of ionic charge and ionic radii, predict the crystal structure for ki by answering the following questions. you may use the tables of slide #18 of module 4.1. (1) for ki, what is the cation - to - anion radius ratio? ratio select 0.127 0.267 0.627 1.23 (2) what is the predicted crystal structure for ki? select

Explanation:

Step1: Identify ionic radii

Look up the ionic radii of $K^+$ and $I^-$. Typically, the ionic radius of $K^+$ is around 1.38 Å and of $I^-$ is around 2.20 Å.

Step2: Calculate cation - to - anion radius ratio

The cation - to - anion radius ratio ($r_{cation}/r_{anion}$) for $KI$ is $\frac{1.38}{2.20}\approx0.627$.

Step3: Predict crystal structure

Based on radius - ratio rules:

• For a ratio in the range of 0.414 - 0.732, the crystal structure is likely to be face - centered cubic (rock - salt type). Since the calculated ratio for $KI$ is 0.627, the crystal structure of $KI$ is face - centered cubic (rock - salt type).

Answer:

(1) 0.627
(2) Face - centered cubic (rock - salt type)