Shifting Reactions A

We will look at some chemical reactions at the microscopic level and at the macroscopic level to understand some new characteristics of reactions.

View the movie on the right and answer the following three questions:

1. Identify when you think the reaction is over/complete. Answer

2. Do either of the reactants completely react? Answer

3. Is there anything interesting about the amounts of reactants reacting and products forming in the reaction? Answer

Let's look at this reaction:

View the movie on the right and answer the following question:

4. How is this reaction related to the first reaction above? Answer

View the movie on the right and answer the following question:

5. Is this reaction similar to the first reaction, or different? How is this reaction similar, or different? Answer

View the movie on the right and answer the following question:

6. Is this reaction similar to the first reaction, or different? How is this reaction similar, or different? Answer


Reactions fall into two categories: reversible and irreversible reaction. Reversible reactions have three characteristics: 1) the reaction proceed in both directions, left to right and right to left; 2) all reactants and products are present in the reaction container; 3) at the macroscopic level the reaction appears to stop, when in fact at the microscopic level the reaction does not stop. In irreversible reactions one of the reactants is called the limiting reagent because it reacts completely, and the other reactant is the excess reagent. We have investigated irreversible reactions in the discussion on stoichiometry, limiting reagents and solution stoichiometry.