Question

CO(g) + H2O --> CO2 (g) + H2(g)

kC = 4.06 at 500 C degree.

2.8g CO , 1.8g H2O placed in a 1.00 litter

a/ calculate Kp

b/ What are the concentrations of reactants and products at equilibrium

Answer 1

Kc = 4.06 = [CO2][H2]/[CO][H2O]

Initial concentrations of CO and H2O are 0.100 M each

Assume that x mol/L of CO2 and H2 are formed. Equilibrium concentrations will be:
[CO] = [H2O] = 0.1 - x
[CO2] = [H2] = x.

So, Kc = 4.06 = x^2 / (0.1-x)^2

Since the right side of the equation is a perfect square, the easiest way to begin solving is to take the square root of both sides. That gives
2.015 = x/.1-x

x=0.067You defined x to be the equilibrium concentrations of CO2 and H2. The equilibrium concentrations of CO and H2O are 0.100 -0.067=0.033.