Question

Which stoichiometric defect cause increase in density of solid

Answer 1

Firstly let me clear it to you that, there are two types of stoichiometric defects, namelySchottky defects : The absence of a cation or anion from the position which it is expected to occupy in the periodic arrangement of ions.                      Since, the solid with a Schottky defect contains lesser of ions as compared to a perfect crystal, the density of the crystal exhibiting Schottky defect will be less as compared to that of the perfect crystal.Frenkel defects : In this type, the ion of being in its expected location is found in one of the interstices.                      The density of crystals exhibiting Frenkel defect remains unchanged as the ions are present in the interstitial sites without changing the volume of the substance.
               In interstitial defect vacancy is not created but an interstitial atom exists hence, density increases.

hope it helps

Answer 2

In interstatial defect density of solid increase because externally number of shpere increase I hope this help for you plzzz mark me,