Solubility product of a salt AB, is 4 x 10 9 in asolution in which con

1.	Solubility product of a salt AB, is 4 x 10 9 in asolution in which concentration of A2+is 10-3 M.The salt will precipitate when the concentration ofB becomes2 x 10 3 M12) 2 x 10 M13) 4 x 10-6 M(4) 4 x 10-3 M
Answer» Correction: $\\\tt k_{sp} = <klux>4</klux>* 10^{-9}$ Your value is WAY too large. Solution: Option D. $\\\tt 4* 10^{-5}$ Theory Used: The solubility product CONSTANT is given by, $\\\tt K_{sp} = [A ^ {a+}][ B ^ {b-}]$ Therefore, $\\\tt k_{sp} = [A^+][B^-]$ Using Question DATA: $\\\tt k_{sp} = 10^{-3} [B^-] \\\tt 4 (10^{-9}) = 10^{-3} [B^-] \\\tt [B^-] = 410^{-6}$ The precipitation will start when $\\\tt [B^-] > 4 10^{-6}$ Which is in option (4)