Arrhenius acids and bases make up a class of compounds, which include many of many of our most common compounds and laboratory reagents. Acids are substances that reacts with water to produce hydronium ion, H3O+, and bases are substances that produces hydroxide ion, OH-, in water. One comes in contact with acids and bases multiple times a day, whether it be the acids in vinegar and citrus juices or bases in drain cleaners and household ammonia. .
One of the most important properties of acids and bases is their reaction with each other, also known as neutralization. The word "neutralization" is used because the properties of H+ and OH- are destroyed or neutralized. For example, when the solutions of sulfuric acid, H2SO4 (aq), and the base ammonium hydroxide, NH4OH (aq), are mixed the following reaction occurs.
H2SO4 + 2 NH4OH (NH4)2SO4 + 2 HOH.
When a 1-to-1 mole ratio occurs, both the properties of the acids and bases disappear and the resulting solution becomes neutral, a pH of 7. A Bronsted-Lowry acid is defined as a species that donates a proton (H+) and a Bronsted-Lowry base is defined as a species that accepts a proton. Conjugate acids and conjugate bases are the acids and bases that lose or gain protons. In a neutralization reaction, an acid and a base reacts to form a conjugate base and a conjugate acid. Ionic compounds are said to be strong electrolytes. They break up essentially 100% into ions in water, and since there are so many ions, they are very strong conductors of electricity. Acids and bases that essentially complete their ionization in water are also strong electrolytes, and are considered strong acids and strong bases. However, most acids and bases are not completely ionized in water. As a result two opposing reactions simultaneously occur, one that removes ions and one that forms ions. Once a balance is achieved when ions react and are produced at the same rate, chemical equilibrium has occurred.
