Question

Which of the following have coordination number 4:8?

• A. ${\mathrm{Li}}_{2}O$
• B. ${\mathrm{BaCl}}_2$
• C. ${\mathrm{Rb}}_{2}O$
• D. $K_{2}O$

Answer 1

Answer: (A), (C), (D)

$K_{2}O$

Out of these $K_{2}O$ ,${\mathrm{Rb}}_{2}O$ ,${\mathrm{Li}}_{2}O$ have antifluorite structure. So the coordination number is 4:8
${\mathrm{BaCl}}_2$ has fluorite structure and coordination number is 8:4