Consider the reaction Fe3+(aq) + SCN (aq) FESCN²+(aq) How will the equilibrium position shift if a. water is added, doubling the volume? b. AGNO3(aq) is added? (AgSCN is insoluble.) c. NaOH(aq) is added? [Fe(OH)3 is insoluble.] d. Fe(NO3)3(ag) is added?

The following question is taken from a Chemistry Advanced Placement Examination and is used with the permission of the Educational Testing Service. Solve the following problem: MgF2(s)Mg2+(aq)+2F(aq) In a saturated solution of MgF2 at 18 C, the concentration of Mg2+ is 1.21103M . The equilibrium is represented by the preceding equation. (a) Write the expression for the solubility-product constant, Ksp, and calculate its value at 18 C. (b) Calculate the equilibrium concentration of Mg2+ in 1.000 L of saturated MgF2 solution at 18 C to which 0.100 mol of solid KF has been added. The KF dissolves completely. Assume the volume change is negligible. (c) Predict whether a precipitate of MgF2 will form when 100.0 mL of a 3.00103 -M solution of Mg(NO3)2 is mixed with 200.0 mL of a .2.00103 -M solution of NaF at 18 C. Show the calculations to support your prediction.. (d) At 27 C the concentration of Mg2+ in a saturated solution of MgF2 is 1.17103M . Is the dissolving of MgF2 in water all endothermic or an exothermic process? Give an explanation to support your conclusion.

Chromium(VI) forms two different oxyanions, the orange dichromate ion, Cr2O72 , and the yellow chromate ion, CrO42 . (See the following photos.) The equilibrium reaction between the two ions is Cr2O72(aq)+H2O(l)2CrO42(aq)+2H+(aq) Explain why orange dichromate solutions turn yellow when sodium hydroxide is added.

Magnesite (magnesium carbonate, MgCO3) is a common magnesium mineral. From the solubility product constant, find the solubility of magnesium carbonate in grams per liter of water.

Some barium chloride is added to a solution that contains both K2SO4 (0.050 M) and Na3PO4 (0.020 M). (a) Which begins to precipitate first: the barium sulfate or the barium phosphate? (b) The concentration of the first anion species to precipitate, either the sulfate or phosphate, decreases as the precipitate forms. What is the concentration of the first species when the second begins to precipitate?

The ore cinnabar (HgS) is an important source of mercury. Cinnabar is a red solid whose solubility in water is 5.5 X 10-2 mol L-1. Calculate its \p. What is its solubility' in grams per 100 g of water?

What is the effect on the amount of solid Mg(OH)2 that dissolves and the concentrations of Mg2+ and OH- when each of the following are added to a mixture of solid Mg(OH)2 and water at equilibrium? (a) Mgcl2. (b) KOH. (c) HClO4. (d) NaNO3. (e) Mg(OH)2

Consider the reaction BaF2(s)+SO42(aq)BaSO4(s)+2 F(aq) (a) Calculate K for the reaction. (b) Will BaSO4 precipitate if Na2SO4 is added to a saturated solution of BaF2?

Consider the equilibrium curve for AgCl shown below. Which of the following statements about a solution at point A on the curve are true? (a) The solution is saturated and at equilibrium. (b) Addition of NaCl increases the concentration of Cl- in solution. (c) Addition of NaCl increases the concentration of in solution. (d) Addition of Ag+ results in the precipitation of AgCl. (e) Addition of solid NaNO3 to the solution without change in volume does not change [Ag+] or [Cl-].

Calculate the solubility (in grams per liter) of silver chloride in the following. (a) pure water (b) 0.025 M BaCl2 (c) 0.17 M AgNO3