Chapter 12, Problem 83E

Interpretation Introduction

(a)

Interpretation:

The type of cubic cell unit adopted by CaO needs to be determined.

Concept introduction:

To find the type of unit cell adopted by crystal lattice, ratio between the ionic radius of cation and the anion $\left({\text{r}}_{cation}{\text{/R}}_{anion}\right)$ is used.

$\text{If 0}\text{.225 < }\left(\frac{{\text{r}}_{\text{cation}}}{{\text{R}}_{\text{anion}}}\right)\text{ < 0}\text{.414 }$

Then, a tetrahedral hole of the FCC array of anions occupied by the cation.

$\text{If 0}\text{.414 < }\left(\frac{{\text{r}}_{\text{cation}}}{{\text{R}}_{\text{anion}}}\right)\text{ < 0}\text{.732 }$

Then, an octahedral hole of FCC array of anions occupied by the cation.

$\text{If 0}\text{.732 < }\left(\frac{{\text{r}}_{\text{cation}}}{{\text{R}}_{\text{anion}}}\right)$

Them, a cubic hole of simple cubic array of anions occupied by the cation.

Interpretation Introduction

(b)

Interpretation:

The type of cubic cell unit adopted by CuCl needs to be determined.

Concept introduction:

To find the type of unit cell adopted by crystal lattice, ratio between the ionic radius of cation and the anion $\left({\text{r}}_{cation}{\text{/R}}_{anion}\right)$ is used.

$\text{If 0}\text{.225 < }\left(\frac{{\text{r}}_{\text{cation}}}{{\text{R}}_{\text{anion}}}\right)\text{ < 0}\text{.414 }$

Then, a tetrahedral hole of the FCC array of anions occupied by the cation.

$\text{If 0}\text{.414 < }\left(\frac{{\text{r}}_{\text{cation}}}{{\text{R}}_{\text{anion}}}\right)\text{ < 0}\text{.732 }$

Then, an octahedral hole of FCC array of anions occupied by the cation.

$\text{If 0}\text{.732 < }\left(\frac{{\text{r}}_{\text{cation}}}{{\text{R}}_{\text{anion}}}\right)$

Them, a cubic hole of simple cubic array of anions occupied by the cation.

Interpretation Introduction

(c)

Interpretation:

The type of cubic cell unit adopted by LiO₂ needs to be determined.

Concept introduction:

To find the type of unit cell adopted by crystal lattice, ratio between the ionic radius of cation and the anion $\left({\text{r}}_{cation}{\text{/R}}_{anion}\right)$ is used.

$\text{If 0}\text{.225 < }\left(\frac{{\text{r}}_{\text{cation}}}{{\text{R}}_{\text{anion}}}\right)\text{ < 0}\text{.414 }$

Then, a tetrahedral hole of the FCC array of anions occupied by the cation.

$\text{If 0}\text{.414 < }\left(\frac{{\text{r}}_{\text{cation}}}{{\text{R}}_{\text{anion}}}\right)\text{ < 0}\text{.732 }$

Then, an octahedral hole of FCC array of anions occupied by the cation.

$\text{If 0}\text{.732 < }\left(\frac{{\text{r}}_{\text{cation}}}{{\text{R}}_{\text{anion}}}\right)$

Them, a cubic hole of simple cubic array of anions occupied by the cation.