Journal Entry:

 Which of the following statements most accurately describes a reaction at equilibrium?
(A) The forward and reverse reaction rates are zero.
(B) At equilibrium, there is no net driving force for either the forward or reverse reaction.
(C) The concentration of products is equal to the concentration of reactants and their concentrations do not change over time.
(D) The equilibrium state is reached when both the entropy and energy of the system are at a maximum.

Learning Intentions

• We will learn about common processes and reactions that are reversible.

• We will learn how to determine if a reaction is in equilibrium

• We will learn what Q is for a reversible reaction and how it is calculated.

• We will learn how to calculate K for a reaction in equilibrium.

Closing Task:

You can determine if a reaction is in equilibrium and how to calculate K for that reaction.

Content Standards being covered:

In many classes of reactions, it is important to consider both the forward and reverse reactions. (E.K. 6.A.1)

The current state of a system undergoing a reversible reaction can be characterized by the extent to which reactants have been converted to products. The relative quantities of reaction components are quantitatively described by the reaction quotients, Q. (E.K. 6.A.2)

When a system is at equilibrium, all macroscopic variables, such as concentration, partial pressures, and temperature, do not change over time. Equilibrium results from an equality between the rates of the forward and reverse reactions, at which point Q=K. (E.K. 6.A.3)