What Makes a Substance Acidic?
Determining if a substance is acidic is integrally related to what makes the substance acidic. This topic is of vital importance for a number of applications, including gardening, farming, medicinal, cosmetic, industrial and more.
Other People Are Reading
-
Definition of an Acid
-
In our everyday experience we understand and relate acids to the definition given by Arrhenius. The Arrhenius definition of an acid says that an acid is any electrolyte (something that dissolves in water) that contains one or more hydrogen atoms and produces H+ ions when dissolved in water. To make a substance acidic then would require you to add H+ ions to it.
Relative Strength of Acids
-
Acids are categorized as both weak and strong. The difference all depends on the molecule that is supplying the H+ ions. If the molecules like to keep some H+ for itself it will be called a weak acid. On the other hand if a molecule likes to "give away" all of its H+ then it will be classified a strong acid.
-
Physical Characteristics of an Acid
-
The word acid comes from the Latin word "acidus," meaning "sour." Early chemists gave them this name because of their sour taste. We possess enough knowledge now to know that we should never taste any chemical without knowing its effects on the body.
Molecules that Make up Acids
-
The molecules that are considered acidic must be capable of donating an H+ ion. That is, they have a labile hydrogen atom. If one were to look at the Lewis structure of an acid you would see a hydrogen atom at the "edge" of the molecule that could readily come off into a solution. Given the chemical make-up we should see hydrogen atoms on the outside of the compound (for example, HCl, H2SO4, CH3COOH).
The pH Scale and Acids
-
Acids have a pH value of less than 7. The pH scale give us an easy way to determine if a substance is acidic and is calculated directly from the concentration of H+ ions in a solution.
-
References
Resources
- Photo Credit Image by Flickr.com, courtesy of Andrew Comings
