Ch. 17  equilibrium                  test       [70 points]


For problems involving calculations, show your work in an organized manner, include any relevant equation (or formula and conversion factor(s)), put the proper units in your calculations / answer, and have the proper number of significant figures in your answer.   


Academic Honesty:   The answers on this test are my own and I am using only the allowed set of notes as described in the syllabus.  I have not discussed the test questions with anyone before or during the test nor have I seen the test questions prior to the exam.  If you violate any of the preceding items or do not sign, your semester grade is a F.


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1. In regards to the reaction:  N2(g)  +  3 H2(g)    2 NH3(g) , there was initially 25 g N2, 5.0 g H2, and 35.0  g NH3 in a 5.0 L container.  At equilibrium, there is 25.0 g NH3.  Based on the preceding information, what is the equilibrium constant, Kc, for this reaction ?  [15 points]


2.  In regards to the reaction:  H2(g)  +  Cl2(g)    2 HCl(g) ;  Kp  = 10.0, the initial partial pressure of H2, Cl2, and HCl was 325 torr, 1235 torr, and 9725 torr, respectively.  What is the equilibrium partial pressure of HCl ?  [20 points] 


3. Write the algebraic expression for the equilibrium constant, Kc, for the reaction  __.  [15 points]


a.   N2(g)  +  3 H2(g)    2 NH3(g)


      b.  C2H6(g)  +  O2(g)     CO2(g)   +  H2O(l)


      c.  The net ionic equation describing mixing aqueous solutions of calcium nitrate and sodium phosphate

In regards to the reaction:  2 SO2(g)  + O2(g)   2 SO3(g) , what is the effect on the concentration of SO3 ?  justify / rationalize your response.  [20 points]

   a.  Cooling the system at constant volume

   b.  Adding Ar at constant volume and temperature

   c.  adding Ar at constant pressure and temperature

   d.  adding O2 at constant volume and temperature