Phosphorous pentachloride decomposes according to the reaction PCl5(g)−⇀↽−PCl3(g)+Cl2(g) A 13.9 g sample of PCl5 is added to a sealed 1.50 L flask and the reaction is allowed to come to equilibrium at a constant temperature. At equilibrium, 43.8% of the PCl5 remains. What is the equilibrium constant, Kc , for the reaction? Kc=

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?

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.

The value of the equilibrium constant, K, is dependent on which of the following? (There may be more than one answer.) a. the initial concentrations of the reactants b. the initial concentrations of the products c. the temperature of the system d. the nature of the reactants and products Explain.

The decomposition of NH4HS, NH 4 HS( s )NH3( g )+ H 2 S( g ) is an endothermic process. Using Le Chatelier's principle, explain how increasing the temperature would affect the equilibrium. If more NH4HS is added to a flask in which this equilibrium exists, how is the equilibrium affected? What if some additional NH3 is placed in the flask? What will happen to the pressure of NH3 if some H2S is removed from the flask?

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.

12.101 An engineer working on a design to extract petroleum from a deep thermal reservoir wishes to capture toxic hydrogen sulfide gases present by reaction with aqueous iron(II) nitrate to form solid iron(II) sulfide. (a) Write the chemical equation for this process, assuming that it reaches equilibrium. (b) What is the equilibrium constant expression for this system? (c) How can the process be manipulated so that it does not reach equilibrium, allowing the continuous removal of hydrogen sulfide?

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 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

What is Le Chteliers principle? Consider the reaction 2NOCI(g)2NO(g)+Cl2(g) If this reaction is at equilibrium. what happens when the following changes occur? a. NOCI(g) is added. b. NO(g) is added. c. NOCI(g) is removed. d. Cl2(g) is removed. e. The container volume is decreased. For each of these changes, what happens to the value of K for the reaction as equilibrium is reached again? Give an example of a reaction for which the addition or removal of one of the reactants or products has no effect on the equilibrium position. In general, how will the equilibrium position of a gas-phase reaction be affected if the volume of the reaction vessel changes? Are there reactions that will not have their equilibria shifted by a change in volume? Explain. Why does changing the pressure in a rigid container by adding an inert gas not shift the equilibrium position for a gas-phase reaction?