Honors Chemistry                                                                              Name__________________________

Equilibrium Worksheet

Mr. McAfoos                                                                                    Period_______ Date______________

 

Questions 1-3 pertain to the reaction:    N2O4  ⇄ 2 NO2

 

1. At equilibrium the [NO2] = 2x10-4 M while the [N2O4] = 2.11 M.  What is the value of K?

 

2. If the reaction above is at equilibrium and the [N2O4] = 1.55 M, what is the concentration of the NO2?

 

3. For each of the following cases, determine whether or not the mixture is at equilibrium and if it is not determine what the equilibrium concentrations will be.

a) [N2O4] = 4.00, [NO2] = 8.7x10-3

b) [N2O4] = [NO2] = 3.11 M

c) [N2O4] = 3.1x10-4 M, [NO2] = 2.44 M

d) [N2O4] = 0.335 M, [NO2] = 7.97 x10-5 M

e) [N2O4] = 0.00 M, [NO2] = 1.20 M

f) [N2O4] = 4.55 M, [NO2] = 0.00 M

 

4. For each of the following reactions, complete and balance it and write the formula for Keq.

a) barium nitrate reacts with aluminum sulfate

b) ammonium carbonate reacts with lithium dichromate

c) ethanol (C2H5OH) burns

d) ferric oxide decomposes

 

5. For the reaction  N2(g)  +  3 H2(g) ⇄  2 NH3(g)

[N2] = 2.12 M, [H2] = 1.75x10-5 M, [NH3] = 84.3 M at equilibrium what is the value of K?

 

6.  Use the value of K found in # 5 to determine whether each of the following mixes are at equilibrium and if they are not determine which direction they will run to reach equilibrium. Then determine what the equilibrium concentrations will be

a) [N2] = 0.212 M, [H2] = 0.175 M, [NH3] = 8.43 M

b) [N2] =  [H2] = 1.75 M, [NH3] = 84.3 M

c) [N2] = 2.12 M, [H2] = [NH3] = 84.3 M

 

7.  Use the K from #12 to determine what each of the missing concentrations are at equilibrium. For those mixtures not at equilibrium, determine what the equilibrium concentrations will be.

a)[N2] = 212 M, [H2] = 175 M, [NH3] = ? M

b) [N2] = [H2] = ? M, [NH3] = 0.843 M

c) [N2] = 2.12 M, [H2] = ? M, [NH3] = 1.00 M

 

15.  K for the reaction CH4(g) ⇄ C(s) + 2 H2(g) is 2.5 x 10- 9.

If the [CH4] is initially 1.00 M (and if nothing else is there), what will the final concentration of hydrogen be when equilibrium is reached? (A little trick…solids NEVER show up in the formula for K!)