Question

The solubility products of `MA, MB, MC` and MD are `1.8xx10^(-10), 4xx10^(-3), 4xx10^(-8)` and `6xx10^(-5)` respectively. If a `0.01M` solution of MX is added dropwise to a mixture containing `A^(-), B^(-), C^(-)` and `D^(-)` ions, then the one to be precipitated first will be:
A. MA
B. MB
C. MC
D. MD

Answer 1

Correct Answer - A
`K_(SP)=[M^(+)][anion]`,
`[A^(-)]=(1.8xx10^(-10))/(0.01), [B^(-)]= (4xx10^(-3))/(0.01)`
`[C^(-)]= (4xx10^(-8))/(0.01),, [D^(-)]= (6xx10^(-5))/(0.01)`
Thus `[A^(-)]` is smallest and the product of ionic concentration will exceed its `K_(SP)` in MA to show precipitation first.