Hydrogen peroxide decays into water and oxygen H2O2(aq) ---> H2O(l) + 1/2 O2(g) If we begin with 0.100 M H2O2 with a K value of 4.2 x 10-3 and stop the reaction after 320 seconds, would you

In a particular experiment, the equilibrium constant measured for the reaction, Cl2(g)+NO2(g)Cl2NO2(g), is 2.8. Based on this measurement, calculate AG° for this reaction. Calculate AG° using data from Appendix E at the back of the book and discuss the agreement between your two calculations.

Because calcium carbonate is a sink for CO32- in a lake, the student in Exercise 12.39 decides to go a step further and examine the equilibrium between carbonate ion and CaCOj. The reaction is Ca2+(aq) + COj2_(aq) ** CaCO,(s) The equilibrium constant for this reaction is 2.1 X 10*. If the initial calcium ion concentration is 0.02 AI and the carbonate concentration is 0.03 AI, what are the equilibrium concentrations of the ions? A student is simulating the carbonic acid—hydrogen carbonate equilibrium in a lake: H2COj(aq) H+(aq) + HCO}‘(aq) K = 4.4 X 10"7 She starts with 0.1000 AI carbonic acid. What are the concentrations of all species at equilibrium?

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.