Suppose that in an equilibrium mixture of HCl, Cl2, and H2, the concentration of H2 is 1.0 x 10-11 mol-L-1and that of Cl2 is 2.0 x 10-10 mol-L-1.  What is the equilibrium molar concentration of HCl at 500 K, given Kc = 4.0 x 1018 for H2(g) +Cl2(g) ⇆ 2HCl(g).

Write an equation for an equilibrium system that would lead to the following expressions (ac) for K. (a) K=(Pco)2 (PH2)5(PC2H6)(PH2O)2 (b) K=(PNH3)4 (PO2)5(PNO)4 (PH2O)6 (c) K=[ ClO3 ]2 [ Mn2+ ]2(Pcl2)[ MNO4 ]2 [ H+ ]4 ; liquid water is a product

A solution is prepared by dissolving 0.050 mol of diiodocyclohexane, C5H10I2, in the solvent CCl4.The total solution volume is 1.00 L When the reaction C6H10I2 C6H10 + I2 has come to equilibrium at 35 C, the concentration of I2 is 0.035 mol/L. (a) What are the concentrations of C6H10I2 and C6H10 at equilibrium? (b) Calculate Kc, the equilibrium constant.

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?

Describe a nonchemical system that is not in equilibrium, and explain why equilibrium has not been achieved.

For the reactionH2(g)+I2(g)2HI(g), consider two possibilities: (a) you mix 0.5 mole of each reactant. allow the system to come to equilibrium, and then add another mole of H2 and allow the system to reach equilibrium again. or (b) you mix 1.5 moles of H2 and 0.5 mole of I2 and allow the system to reach equilibrium. Will the final equilibrium mixture be different for the two procedures? Explain.

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 decomposition of PCl5(g) to form PCl3(g) and Cl2(g) has Kc = 33.3 at a high temperature. If the initial concentration of PCl5 is 0.1000 M, what are the equilibrium concentrations of the reactants and products?

For the system SO3(g)SO2(g)+12 O2(g)at 1000 K, K=0.45. Sulfur trioxide, originally at 1.00 atm pressure, partially dissociates to SO2 and O2 at 1000 K. What is its partial pressure at equilibrium?

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?