Question

How many milligrams of $AgBr$ will dissolve in water to given 20 L of aqueous solution $K_{sp}$ of $AgBr$ $=5.0\times {10}^{-13}$ ? (mol. wt. of AgBr$=$188)

• A. 1.66
• B. 3.66
• C. 2.66
• D. 4.66

Answer 1

The correct option is C 2.66

$AgBr\rightleftharpoons A{g}^{+}+B{r}^{-}$

$K_{sp}=s^2=5.0\times 10^{-13}=50\times {10}^{-14}$

$s=7.07\times {10}^{-7}moles{L}^{-1}$

Weight $=M\times V\times M_B\times 1000=7.07\times {10}^{-7}\times 20\times 188\times 1000mg=2.66mg$