Note that, if any of the reactants or products are in the liquid or solid states, these are not included in the expression of the equilibrium constant.įor example, consider the following general reaction: If the reactants and products are gases, we can also calculate the equilibrium constant using pressures, in this case the equilibrium constant is called #K_P#: What would be the equilibrium concentration of all products and reactants? Click here for answer.The equilibrium constant of a reaction under the general form:Ĭan be calculated by the general expression of #K_(eq)# as follows: Assume Keq=1.8x10 -5 and the initial conditions to be the following: = 3.0M = 0.50M = 0.50M. Now try a calculation using the acetic acid dissociation described above.If a flask contains HI at a pressure of 200 mmHg, H 2 at a pressure of 10 mmHg, and I 2 at a pressure of 4 mmHg, will the system produce more reactants or more products to reach equilibrium? Click here for answer. Given the following equation: H 2 (g) + I 2 (g) 2 HI (g) Keq=20.What would the equilibrium concentrations be for and ? Click here for answer.

After putting in pure acetic acid and allowing the system to equilibrate you measure the hydrogen ion concentration to be 0.150 M.

What happens when the system comes to equilibrium? Why?

If you put in a small number for the acid concentration, a large number for one of the ion concentrations, and then put in zero for the other ion concentration.What do you notice about the value for Keq?.Type in several different starting concentrations above.Try starting with different amounts of reactants and products and push the equilibrate button to see what the equilibrium conditions will be. Consider the following reaction: HC 2H 3O 2 (aq) H +1 (aq) + C 2H 3O 2 -1 (aq).pure liquids or solids don't have any affect on the final result of Keq, so they are not included in its calculation if these types of substances are present in the reaction.The equilibrium constant would be calculated as: All substances are either gasses or solutions (no solids or pure liquids).There are two classifications of reactions that are necessary to write proper equilibrium constants: homogeneous and heterogeneous equilibria.The equilibrium constant will be represented by the symbol Keq. The ratio of products to reactants is a constant. As you have seen from the computer lab simulations.

How to calculate keq