Question

An ionic compound AB has ZnS type of structure, if the radius of A+ is 22.5 pm, then the ideal radius of B- is

• A.
  54. 35 pm
• B. 100 pm
• C.
  145. 16 pm
• D. None

Answer 1

Answer: (B)

100 pm

Answer 2

Since ionic compound AB has Zns type of structure, therefore it has tetrahedral holes, for which

$\frac{radiusofcation}{radiusofanion} = 0.225$

$\frac { \mathrm { r } ^ { + } } { \mathrm { r } _ { - } } = 0.225$

$\frac { 22.5 } { r _ { - } } = 0.225$

Hence r- = 100 pm