Easy Key Concepts of Acids and Bases in Chemistry

Acids and Bases are two very important classes of compounds, and it's important for student studying chemistry to understand the concept. Luckily, with only a few key points, acids and bases turn into pretty straightforward chemistry.

Acids were discovered over 700 years ago, but it was Svante Arrhenius in the 1800s, a Swedish physics student, who first found the essential nature of acids. Arrhenius found that the ability for a solution to conduct electricity was dependent on the presence of ions, atoms that have gained or lost electrons. He did experiments with different types of substances, and whenever he dissolved certain substances in water, the solution would always conduct electricity. Examples are hydrochloric, nitric, and sulfuric acid. Thus, based on his own observations, Arrhenius concluded that these substances all must produce an H+ ion when they are dissolved in water, and this became the definition for an acid.

In addition, Arrhenius discovered that the solution that was produced was a very strong conductor of electricity, so he took this as a proof that almost every single molecule dissociated to give ions. Because the solution was such an efficient conductor, he called these strong electrolytes a strong acid. These definitions hold true to today's science.

Arrhenius also did enormous contribution towards the study on basic solutions, essentially the opposite of an acid. A base, he defined, is a substance that produces hydroxide ions (OH-) when it is dissolved in water, after performing experiments on bases such as sodium hydroxide (NaOh). Just like the acids, these bases would dissolve into virtually 100% ions, and the solution would be a very good conductor of electricity. Therefore, certain bases can also be called strong electrolytes, or strong bases.

When strong acids and strong bases are mixed, there is a chemical reaction that occurs between the OH- and the H+ ions, to produce water. The rest of the ions in the acid and base become dissolved in the water, without any reaction in between them. They are just floating in the solution, and can therefore be called spectator ions.

As an example, when NaOh (base) reacts with HCl (acid), the only chemical reaction that takes place is that water is produced. The Oh- will combine with the H+ ion, to give H2O. The sodium and chloride are spectator ions, because they never undergo a change. This is one of the most important key concepts about acids and bases to understand. Water is always the product of an acid-base reaction. The other product is a salt between the metal and nonmetal, but since it remains dissolved in the solution, it's not a chemical reaction.