When `1.88 g` of AgBr(s) is added to a `10^(-3)` M aqueous solution of KBr, the concentrationof Ag is `5xx10^(-10)`M. If the same amout of AgBr(s) is added to a `10^(-2)` M aqueous solution of `AgNO_(3)`, the concentration of `Br^(-)` is

Options

A. `9.4 xx 10^(-9)` M
B. ` 5 xx 10^(-10)` M
C. `1 xx 10^(-11)` M
D. ` 5 xx 10^(-11)` M

Answer

D

Explanation

`"AgBr"_((s))hArr Ag_((aq))^(+) +Br_((aq))^(-)`
`K_(sp(AgBr)) =[Ag^(+)] [Br^(-)] `
` = ( 5 xx 10^(-10)) (10^(-3))`
`= 5 xx10^(-13)`
Now, ` 5 xx 10^(-13) = (10^(-2)) [Br^(-)] `
`[Br^(-)] = 5 xx 10^(-11) M `.