Pure solid NH4HSE is placed in an evacuated container at 24.8°C. Eventually, the pressure above the solid reaches the equilibrium pressure 0.0184 atm due to the reaction NH,HSe(s) 2 NH;(g) + H,Se(g) (a) Calculate the equilibrium constant of this reaction at 24.8°C. (b) In a different container, the partial pressure of NH3(g) in equilibrium with NH,HSe(s) at 24.8°C is 0.0252 atm. What is the partial pressure of H,Se(g)?

Describe a nonchemical system that is in equilibrium, and explain how the principles of equilibrium apply to the system.

Hydrogen gas and iodine gas react to form hydrogen iodide. If 0.500 mol H2 and 1.00 mol I2 are placed in a closed 10.0-L vessel, what is the mole fraction of HI in the mixture when equilibrium is reached at 205C? Use data from Appendix C and any reasonable approximations to obtain K.

The diagram represents an equilibrium mixture for the reaction N2(g) + O2(g) ⇌ 2 NO(g) Estimate the equilibrium constant.

Methanol can be synthesized by means of the equilibriumreaction CO(g)+2H2(g)CH3OH(g) for which the equilibrium constant at 225°C is 6.08103. Assume that the ratio of the pressures of CO(g) and H2(g) is 1:2. What values should they have if the partial pressureof methanol is to be 0.500 atm?

Explain why the development of a vapor pressure above a liquid in a closed container represents an equilibrium. What are the opposing processes? How do we recognize when the system has reached a state of equilibrium?

12.103 Methanol, CH3OH, can be produced by the reaction of CO with H2, with the liberation of heat. All species in the reaction are gaseous. What effect will each of the following have on the equilibrium concentration of CO? (a) Pressure is increased, (b) volume of the reaction container is decreased, (c) heat is added, (d) the concentration of CO is increased, (e) some methanol is removed from the container, and (f) H2 is added.

. What does it mean to say that a state of chemical or physical equilibrium is dynamic?

At 500C, k for the for the formation of ammonia from nitrogen and hydrogen gases is 1.5105. N2(g)+3H2(g)2NH3(g)Calculate the equilibrium partial pressure of hydrogen if the equilibrium partial pressures of ammonia and nitrogen are 0.015 atm and 1.2 atm, respectively.

If wet silver carbonate is dried in a stream of hot air. the air must have a certain concentration level of carbon dioxide to prevent silver carbonate from decomposing by the reaction Ag2CO3(s)Ag2O(s)+CO2(g) H for this reaction is 79.14 kJ/mol in the temperature range of 25 to 125C. Given that the partial pressure of carbon dioxide in equilibrium with pure solid silver carbonate is 6.23 103 torr at 25C, calculate the partial pressure of CO2 necessary to prevent decomposition ofAg2CO3 at 110C. (Hint: Manipulate the equation in Exercise 79.)