Ch. 17  equilibrium                  test       [75 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) , the initial concentration of N2, H2, and NH3 were 2.0 M, 4.0 M, and 6.0 M, respectively.  The equilibrium concentration of NH3 is 5.0 M.  Based on the preceding information, what is the equilibrium constant, Kc, for this reaction ?  [10 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 1.0 atm, 2.0 atm, and 0 atm, respectively.  What is the equilibrium partial pressure of HCl ?  [15 points]

 

 

 3.  In regards to the reaction:  H2(g)  +  Cl2(g)    2 HCl(g) ;  Kc  = 10.0, the initial concentration of H2, Cl2, and HCl was 1.0 M, 2.0 M, and 6.0 atm, respectively.  What is the equilibrium concentration of HCl ?  [15 points]

 

 

4. 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

 


5. In regards to the reaction:  PCl5(g)    PCl3(g)  +  Cl2(g), what is the effect on the concentration of PCl3 ?  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 Cl2 at constant volume and temperature