Equilibruim

1. Equilibrium is reached when

  a. The concentration of products equals the concentration of reactants  
  b. All reactants have been converted to products  
  c. The concentrations of reactants and products are no longer changing  
  d. The increase in products is occuring at a steady rate  

2. Which of the following is true of a system at equilibrium?  
   a. The rate of the forward reaction is equal to the rate of the reverse reaction.  
  b. The rate constants of the forward and reverse reactions are equal.  
  c. The rate of the forward and reverse reactions are both zero.  
  d. All of the above  

3. In which reaction is the value of Kc equal to the value of Kp?  
   a. N2(g) + O2(g) → 2NO (g)  
  b. 2H2(g) + O2(g) → 2H2O(g)  
  c. CaCO3(s) → CaO(s) + CO2(g)  
  d. H2S(aq) + Zn(s) → ZnS + H2(g)  

4. If the equilibrium constant for a reaction is X, what is the equilibrium constant for the reverse reaction?  
   a. X/2  
  b. 1/X  
  c. -X  
  d. X  

5. For the reaction

2ICl → I2 + Cl2    Kc = 8.3 x 10-4

If the concentrations are as follows: [ICl] = 0.15M, [I2] = 0.0015M, [Cl2] = 0.0075M, which of the following is true

   a. The reaction is at equilibrium  
  b. The concentration of I2 is decreasing  
  c. The concentration of Cl2 is increasing  
  d. All of the above are true