Question

If the close packed cations in an AB type solid with NaCl structure have a radius of 75 pm, what would be the maximum and minimum sizes of the anions filling the voids ?

Answer 1

Correct Answer - 102.5 pm , 181.2 pm
For close packed AB type solid with NaCl structure , `r_+/r_(-)`=0.414-0.732
`therefore` Minimum value of `r_(-)=r_(+)/0.732=75/0.732` pm =102.5 pm , Maximum value of `r_(-)=r_(+)/0.414=75/0.414` =181.2 pm .