InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
Equal volumes of the following `Ca^(2+)` and `F^(-)` solutions are mixed. In which of the solutions will precipitation occur ? `(K_(sp) "of" CaF_(2)=1.7xx10^(-10))` (1) `10^(-2) M Ca^(2+) + 10^(-5) M F^(-)` (2) `10^(-3) M Ca^(2+)+10^(-3)M F^(-)` (3) `10^(-4) M Ca^(2+)+ 10^(-2)M F^(-)` (4)`10^(-2) M Ca^(2+) + 10^(-3) M F^(-)` Select the correct answer using the codes given below:A. `10^(-2) M Ca^(2+) + 10^(-5) M F^(-)`B. `10^(-3) M Ca^(2+) + 10^(-3) M F^(-)`C. `10^(-4) M Ca^(2+) + 10^(-2) M F^(-)`D. `10^(-2) M Ca^(2+) + 10^(-3) M F^(-)` |
|
Answer» Correct Answer - D Ionic product of `CaF_92)=[Ca^(2+)][F^(-)](2)`. Concentration of ions will be halved after mixing. Thus, ionic products will be (1) `(10^(-2))/(2)xx((10^(-5))/(2))^(2)=(1)/(8)xx10^(-12)` (2) `(10^(-3))/(2)xx((10^(-3))/(2))^(2)=(1)/(8)xx10^(-9)` (3) `(10^(-4))/(2)xx((10^(-2))/(2))^(2)=(1)/(8)xx10^(-8)` (4) `(10^(-2))/(2)xx((10^(-3))/(2))^(2)=(1)/(8)xx10^(-8)` In (2), (3) and (4), ionic product `gt K_(sp)`. Hence, precipitation will occur in (2), (3) and (4). |
|