Answer to Question #162815 in General Chemistry for Kimberli

Question

1. Define equilibrium

2. State the meaning of a reversible reaction

3. State the two conditions under which a reaction can reach equilibrium

4. Explain what happens to the reactants and products in a reversible reaction when it is at equilibrium

5. State the three types of equilibrium encountered in chemistry. Give an example for each

6. Explain what these mean when you see them in a chemical equation <——>

Answer 1

1. Chemical equilibrium, a condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs. A reversible chemical reaction is one in which the products, as soon as they are formed, react to produce the original reactants.

2. In principle, all chemical reactions are reversible reactions . This means that the products can be changed back into the original reactants .

3. A reaction is at equilibrium when the amounts of reactants or products no longer change. Chemical equilibrium is a dynamic process, meaning the rate of formation of products by the forward reaction is equal to the rate at which the products re-form reactants by the reverse reaction.

4. Reversible reactions that happen in a closed system eventually reach equilibrium. At equilibrium, the concentrations of reactants and products do not change. But the forward and reverse reactions have not stopped - they are still going on, and at the same rate as each other

5. Chemical equilibrium: When the forward reaction rate equals the reverse reaction rate in a closed system (no energy inputs or outputs)

• Static equilibrium: Amount of reactant and product are fixed and unchanging
• Dynamic equilibrium: Reactant is turning into product and product is turning into reactant, but at the same rate such that the concentrations of each are unchanged on a macroscopic scale

6. This symbol  <——> means reaction can be both from reactant to product and product to reactant

A + B  <——> C + D

C + D  <——> A + B