When NaCl is doped with `MgCl_(2)` the nature of defect produced is

Answer

C

Explanation

When small amount of `MgCl_(2)` is added to NaCl, some of the `Mg^(2+)` ions replace `Na^(+)` ions and occupy the sites earlier occupied by `Na^(+)`. To maintain electrical neutrality of the crystal one more `Na^(+)` leaves the lattice, thus generating, cation vacancy equal to number of `Ca^(2+)` ions added. thus impurity defect is produced.