The value of Kc for the reaction between water vapor and dichlorine monoxide, H2O + Cl2O <=> 2HOCl is 0.0900 at 25 C. Determine the equilibrium concentrations of all three compounds if the starting concentrations of both reactants are 0.00432 M and no HOCl is present.

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?

Calculate the value of the equilibrium constant for the reaction N2(g)+2O2(g)2NO2(g) if the concentrations of the species at equilibrium are [N2] = 0.0013, [O2] = 0.0024, and [NO2] = 0.00065.

Consider 0.200 mol phosphorus pentachloride sealed in a 2.0-L container at 620 K. The equilibrium constant, Kc, is 0.60 for PCl5(g) PCl3(g) + Cl2(g) Calculate the concentrations of all species after equilibrium has been reached.

Suppose a reaction has the equilibrium constant K = 1.3 108. What does the magnitude of this constant tell you about the relative concentrations of products and reactants that will be present once equilibrium is reached? Is this reaction likely to be a good source of the products?

Consider the system 4NH3(g)+3O2(g)2N2(g)+6H2O(l)H=1530.4kJ (a) How will the concentration of ammonia at equilibrium be affected by (1) removing O2(g)? (2) adding N2(g)? (3) adding water? (4) expanding the container? (5) increasing the temperature? (b) Which of the above factors will increase the value of K? Which will decrease it?

Write equilibrium constant expressions for the following reactions. For gases, use either pressures or concentrations. (a) 2 H2O2(g) 2 H2O(g) + O2(g) (b) CO(g) + O2g CO2(g) (c) C(s) + CO2(g) 2 CO(g) (d) NiO(s) + CO(g) Ni(s) + CO2(g)

Use the solubility product constant from Appendix F to determine whether a precipitate will form if 10.0 mL of 1.0 106 M iron(II) chloride is added to 20.0 mL of 3.0 104 M barium hydroxide.

At room temperature, the equilibrium constant Kc for the reaction 2 NO(g) ⇌ N2(g) + O2(g) is 1.4 × 1030. Is this reaction product-favored or reactant-favored? Explain your answer. In the atmosphere at room temperature the concentration of N2 is 0.33 mol/L, and the concentration of O2 is about 25% of that value. Calculate the equilibrium concentration of NO in the atmosphere produced by the reaction of N2 and O2. How does this affect your answer to Question 11?

The atmosphere consists of about 80% N2 and 20% O2, yet there are many oxides of nitrogen that are stable and can be isolated in the laboratory. (a) Is the atmosphere at chemical equilibrium with respect to forming NO? (b) If not, why doesnt NO form? If so, how is it that NO can be made and kept in the laboratory for long periods?