Question

Which of the following order is not correct :-

• A. $CrO<C{r}_2{O}_3<Cr{O}_3$ (covalent character)
• B. $ZnO$ (Philosopher's wool) $>ZnS($ Zinc blend $)$ (ionic character)
• C. $BeC{l}_2>MgC{l}_2>CaC{l}_2>SrC{l}_2>BaC{l}_2$ (ionic character)
• D. $KCl<AgCl$ (covalent character)

Answer 1

Answer: (C)

(i) $C{r}^{+2}O,C{r}_2^{+3}{O}_3,C{r}^{+6}{O}_3$

oxidation state of metal $\uparrow$
polarisation $\uparrow$
covalent character $\uparrow$
(ii) $ZnO\left(O^{-2}\right),ZnS\left(S^{-2}\right)$

anionic size $\uparrow$, polarisation $\uparrow$,
covalent character $\uparrow$, ionic character $\downarrow$
(iii) $BeC{l}_{2}MgC{l}_{2}CaC{l}_{2}SrC{l}_{2}BaC{l}_2$

(cationic size $\uparrow$, polarisation $\downarrow$, ionic character $\uparrow$ )
(iv) $KClAgCl$
$K^{+}\to$ inert gas configuration cation
$A{g}^{+}\to$ Pseudo inert gas configuration cation polarisation power order $\to K^{+}<A{g}^{+}$