[confused20]

I am having difficulty finding the equilibrium pressures of the following problems because of the algebra involved to get the answer.  If anyone could show me the answer in a step by step manner showing he algebra involved, it would be greatly appreciated.  The problems are as follows:

1. 2HI(g) = I2(g) + H2(g)  K= .0169  at 800K

What are the partial pressures at equilibrium of the hydrogen and iodine if initially a sealed flask at 800K contains only HI at a pressure of .200 atm?


2.  SO2(g) + NO2(g) = NO(g) + SO3(g)  K= 84.7

All gases are at an initial pressure of 1.25 atm.  Calculate the partial pressure of each gas at equilibrium.


3.  N2(g) + O2(g) = 2NO(g)  K = .0255

What are the partial pressure of all gases at equilibrium if the initial partial pressure of the gases (both reactants and products) is .300atm?

4.  N2(g) + 3H2(g) = 2NH3(g) K = 1.5 x 10^-5

Calculate the equilibrium partial pressure of hydrogen if the equilibrium partial pressures of ammonia and nitrogen are .015 and 1.2 atm, respectively.