Question

If a solid `A^(o+)B^(ɵ)` having `ZnS` Structure is heated so that the ions along two of the axis passing throgh the face centre particles are lost and bivalent ion `(Z)` enters herre to maintain the electrical neutrality, so that the new formula unit becomes `A_(x)B_(y)C_(c)`, report the value of `x + y + c`.

Answer 1

Correct Answer - 7
For ZnS structure, `(Z_(eff) "of" ZnS=4)`
Number of `B^(o+)`=4/unit.cell (corner+face center)
Number of `A^(o+)=` 4unit/cell (in alternate TVs)
Number of `B^(o+)` ion removed =4 (Two from each face center)
`xx(1)/(2)` (per face center share)=2
Number of `Br^(o+)` ions left=4-2=2/unit cell
Number of `Z^(2-)` ions extering in place of `B^(o+)=1`
[To maintain electrical neutrality, `2B^(o+)=1Z^(2-)`]
Formula=`A_(4)B_(2)Z_(1)`
`therefore x+y+c=4+2+1=7`