Question

if nacl is doped with 10^ -3 mol% of srcl2 . what is the concentration of cation vacancies?

Answer 1

Given,

NaCl is doped with 10^-3 mole % of SrCl₂.This means, 100 moles of NaCl are doped with 10^-3 moles of SrCl₂.

Therefore, 1mole of NaCl is doped with 10^-3 /100 = 10^-5 moles of SrCl₂ or 10^-5 moles of Sr²⁺.

Now,

One Sr²⁺ ion create one cation vacancy.

Therefore, no. of cation vacancies created by 10^-5 moles Sr²⁺

= 10^-5 moles/mole of NaCl

= 10^-5 x 6.022 x 10²³ / mole of NaCl

= 6.022 x 10¹⁸/ mole of NaCl