An aqueous solution contains 0.010 M Br^- and 0.010 M I^-.If Ag⁺ is added until AgBr(s)just begins to precipitate,what are the concentrations of Ag⁺ and I^-? (K_sp of AgBr = 5.4 $\times$ 10^-13,K_sp of AgI = 8.5 $\times$ 10^-17) A) [Ag⁺] = 5.4 $\times$ 10^-11 M,[I^-] = 1.0 $\times$ 10^-2 M B) [Ag⁺] = 8.5 $\times$ 10^-15 M,[I^-] = 1.0 $\times$ 10^-2 M C) [Ag⁺] = 5.4 $\times$ 10^-11 M,[I^-] = 1.6 $\times$ 10^-6 M D) [Ag⁺] = 8.5 $\times$ 10^-15 M,[I^-] = 6.4 $\times$ 10¹ M E) [Ag⁺] = 8.5 $\times$ 10^-15 M,[I^-] = 1.6 $\times$ 10^-6 M

Question

Quizplus · Accepted Answer

Step 1: Write the balanced equation for the precipitation reaction:
AgS1U1P1+S1S1P0 + BrS1U1P1-S1S1P0 → AgBr(s) + S1U1P1+S1S1P0 + BrS1S1P0-
Step 2: Write the expression for the solubility product of AgBr:
KS1U1B1spS1U1B0 = [Ag+] [Br-]
Since solid AgBr(s) just begins to precipitate, [Ag+] will be approximately equal to the concentration of Ag+ initially present in the solution.
Step 3: Calculate the concentration of Ag+ using the stoichiometry of the reaction:
0.010 M of BrS1U1P1-S1S1P0 is present initially, so the concentration of Ag+ must equal the concentration of Br- that reacts with it to form AgBr(s), which is 0.010 M. Therefore, [Ag+] = 0.010 M.
Step 4: Substitute the known values into the expression for the solubility product of AgBr and solve for [Br-]:
KS1U1B1spS1U1B0 = 5.4 F1F1F1S1F1F1F10 10S1U1P1-13S1S1P0 = [Ag+] [Br-] = 0.010 M [Br-]
[Br-] = (5.4 F1F1F1S1F1F1F10 10S1U1P1-13S1S1P0) / 0.010 M = 1.6 F1F1F1S1F1F1F10 10S1U1P1-6S1S1P0 M
Step 5: Use the stoichiometry of the reaction to calculate the change in concentration of IS1U1P1-S1S1P0:
1 mol of Ag+ reacts with 1 mol of Br-, so the concentration of Ag+ that reacts is equal to the change in concentration of Br-. Therefore, [IS1U1P1-S1S1P0] decreases by the same amount as [Br-], which is 0.010 M - 1.6 F1F1F1S1F1F1F10 10S1U1P1-6S1S1P0 M = 0.010 M - 0.016 M = 0.994 M.
Therefore, the concentrations of AgS1U1P1+S1S1P0 and IS1U1P1-S1S1P0 are [AgS1U1P1+S1S1P0] = 5.4 F1F1F1S1F1F1F10 10S1U1P1-11S1S1P0 M and [IS1U1P1-S1S1P0] = 1.6 F1F1F1S1F1F1F10 10S1U1P1-6S1S1P0 M. The correct answer is C.

An Aqueous Solution Contains 0 ×\times× 10-13,Ksp of AgI = 8 ×\times×

An Aqueous Solution Contains 0 $\times$ 10^-13,K_sp of AgI = 8 $\times$