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:

Equal volumes of the following Ca^(2+) and F^(-) solutions are mixed.

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:
Answer» `10^(-2) M Ca^(2+) + 10^(-5) M F^(-)` `10^(-3) M Ca^(2+) + 10^(-3) M F^(-)` `10^(-4) M Ca^(2+) + 10^(-2) M F^(-)` `10^(-2) M Ca^(2+) + 10^(-3) M F^(-)` SOLUTION :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).