Acids, Bases and pH Scales

What is an acid and a base? The first person that tried to define acids and bases was Arrhenius. His theory proposed that an acid is any substance that produces a proton H+, when dissolved in water and the resulting solution is an electrolyte. A base is any substance that produces hydroxide ions, when dissolved in water; they are also called alkali. This theory was able to explain the way acids and bases react; the …

…to which a base removes a proton from water. These results are recorded in a table called the pH scale. This scale is logarithmic which means that point represents a 10x difference with the one below or above. It goes from 0 to 14; 0 being the most acidic substance (hydrochloric acid), 7 being the most neutral substance (simple water) and 14 being the most basic substance (sodium hydroxide). References: Encarta Online Encyclopedia Science Power 10, pages 226-230 Britannica Online Encyclopedia