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If `NaCl` is doped with `10^(-3) mol% GaCl_(3)`, what is the concentration of the cation vacancies? |
Answer» `100 mol` of `NaCl` are doped with `10^(-3) mol` of `GaCl_(3)`. `:. 1 mol` of `NaCl` is doped with `GaCl_(3) = (10^(-3))/(100) = 10^(-5) mol` As one `Ga^(3+)` ion is introduced, three `Na^(o+)` have to be removed to maintain the electrical neutrality. So as one vacancyis filled by `Ga^(3+)`, two cation vacancies are formed. `:.` Concentration of cation vacancy `= 2 xx 10^(-5)` mol/mol of `NaCl` `= 2 xx 10^(-5) xx 6.023 xx 10^(23) mol^(-10)` `= 12.046 xx 10^(-18) mol^(-1)` `= 1.2046 xx 10^(-19) mol^(-1)` |
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