Question

What is the law of mass action? Is it true that the value of K depends on the amounts of reactants and products mixed together initially? Explain. Is it true that reactions with large equilibrium constant values are very fast? Explain. There is only one value of the equilibrium constant for a particular system at a particular temperature, but there is an infinite number of equilibrium positions. Explain.

Answer 1

The Law of mass action is a general description of the equilibrium condition. Guldberg and Waage gave this. The law states that the rate of any given reaction is proportional to the product of the activities (or concentrations) of the reactants.

K is nothing but an equilibrium constant in terms of concentration. This is expressed by using the law of mass action. The equilibrium constant can be expressed as the ratio of the product's concentrations to the product of reactants at equilibrium. So it is independent of the initial concentration.

A Larger K value means greater ease to convert from reactants to products. So reactions are faster.

Each set of equilibrium concentrations is called an equilibrium position. There is only one equilibrium constant for a particular system at a particular temperature, but there is an infinite number of equilibrium positions. The specific equilibrium position depends upon the initial concentrations, but the equilibrium constant does not.