Question
Chemistry Question on The solid state
If NaCl is doped with 10−4mol% of SrCl2, the concentration of cation vacancies will be (NA=6.023×1023mol−1)
A
6.023×1015mol−1
B
6.023×1016mol−1
C
6.023×1017mol−1
D
6.023×1014mol−1
Answer
6.023×1017mol−1
Explanation
Solution
Doping of NaCl with 10−4mol%ofSrCl2 means, 100 moles of NaCl are doped with 10−4molofSrCl2 ∴ 1 mol of NaCl is doped with SrCl2=10010−4=10−6mole As each Sr2+ ion introduces one cation vacancy. ∴ Concentration of cation vacancies =10−6 mol of NaCl =10−6×6.023×1023mol−1 =6.023×1017mol−1