Types of Reactions

Introductory Chemistry - litmus strips for measurement of acidity.For introductory chemistry, there are three types of reactions that will be used:

  • Neutralization (Acids and Bases)
  • Precipitation (two ions forming a solid)
  • Reduction-Oxidation (Redox; involves an exchange of electrons)

A neutralization reaction occurs between an acid and base which results in water and ions in solution as a product if it fully neutralizes. If there is more of either the acid or base, then the solution will either have hydronium ions (H3O+) or hydroxide ions (OH) depending upon which was in excess.

A precipitation reaction occurs when two solutions of ions are mixed together and the ions form a solid due to their low solubility properties. This reaction is noticeable by how a beaker may become cloudy when mixed and after some time, a solid will form at the bottom of the beaker.

A reduction-oxidation (redox) reaction involves a change of oxidation state on atoms within the solution through the exchange of electrons. There is a large list of recorded values of atoms and molecules being reduced (gaining one or more electron(s)) that is used to help determine the cell’s (a system the reaction is taking place) potential.

There are two other major concepts that involve all reactions: Equilibrium and Le Chatelier’s Principle. All reactions will go to equilibrium and stay there until a condition changes to shift the point of equilibrium. Le Chatelier’s Principle manipulates the equilibrium point by changing conditions to favor the products (the end result of the reaction) or reactants (the starting material of the reaction). Some notable conditions that effect reactions are: temperature, ion concentrations for solutions, and pressure for gases.