Equilibrium Problems


1. Write an equilibrium expression for each of the following reactions:
a)  2 H2(g) + O2(g)⇄  2 H2O(g)
b) NH3(aq) + H2O(l)  ⇄  NH4+(aq) + OH-(aq)
 2. Answer True or False: 
        Consider the following equilibrium which employs an iron catalyst:

                             N2(g) + 3 H2(g) ⇄  2 NH3(g) + Thermal Energy 
                              @ a certain Temperature, Kp = 1 x 10-4

3.) A mixture of 0.75 mol of N2(g) and 1.20 mol of H2(g) are placed in a 3.0 liter container with an iron catalyst and heated under pressure to 750K.

                                             N2(g) + 3 H2(g) ⇄  2 NH3(g)

a) When the reaction reaches equilibrium, [H2] = 0.100 M. What is the value of [N2] and [NH3] at equilibrium?
b) If  0.3 moles of ammonia are removed through condensation and no other gases are added, what are the new  concentrations of [H2], [NH3] and  [N2] when the reaction re-establishes equilibrium?
4) The equilibrium constant for the reaction N2O4(g) ⇄  2 NO2(g) at 300K is 0.14. What total pressure would result at equilibrium from placing 2.50g of N2O4(g) into an evacuated 1.50L vessel at this temperature?

5)   3 Fe(s) + 4 H2O(g) ⇄  Fe2O3(s) + FeO(s) + 4 H2(g)

a) Write the expression for Kp.
 
b) Explain the relationship of Kp to Kc for this reaction.
 

c) Explain the effect on the concentrations of water and hydrogen, if the amount of Fe(s) in the reaction were doubled.
 

d) What would occur if the pressure were tripled?
 

e) If you were to place 250 grams of Fe(s) in 1 L of H2O and light a match above the surface, what would you expect to happen? Explain your answer in terms of practical experience and the equilibrium expressions.

6) Fritz Haber was awarded the Nobel prize in 1918 but did not actually receive it until 1920. Did he just forget to pick it up? Why did it take so long?