What does K imply?
Large K > 1 products are "favored", the equilibrium lies to the right
K = 1 neither reactants nor products are favored
Small K < 1 reactants are "favored", the equilibrium lies to the left
How do we calculate K when given concentrations?
Calculate the equilibrium constant (Keq) for the following reaction:
H2 + I2 <==> 2 HI
The first thing to do is write the equilibrium expression for the reaction as written in the problem. This is what to write:
Now, all you have to do is substitute numbers into the problem. Keq is what we want to find, so that's our "x."
Here is what we get:
Solving this and rounding to the correct number of sig figs (remember those??), we get 60.2
How do we calculate K when given Moles and Liters?
At a certain temperature, the equilibrium mixture of PCl5 , PCl3 , and Cl2 has the following concentrations:
[PCl3] = 0.035 M, [PCl5] = 0.017 M, [Cl2] = 0.074 M
Calculate Kc for the reaction PCl3(g) + Cl2(g) <--> PCl5(g)