The term "pH" was first described by Danish biochemist Søren Peter Lauritz Sørensen in 1909. pH is an abbreviation for "power of hydrogen" where "p" is short for the German word for power, potenz and H is the elementsymbol for hydrogen. PH, quantitative measure of the acidity or basicity of aqueous or other liquid solutions. The term, widely used in chemistry, biology, and agronomy, translates the values of the concentration of thehydrogen ion into numbers between 0 and 14.
where a pH below 7 is acidic and a pH greater than 7 is basic. pH of 7 is considered neutral (e.g., pure water). A very strong acids may have a negative pH, while very strong bases may have a pH exceeding 14. pH is important for many chemical, biological, and environmental processes, as it affects the reactivity, solubility, and stability of substances.
For example, pH can influence the growth of plants, the activity of enzymes, the corrosion of metals, and the quality of water. pH is carefully regulated in human cells and blood. The normal pH range for blood is between 7.35and 7.45. Acid rain caused by natural and man-made pollutants changes the acidity of soil and water, greatly affecting living organisms and other processes. In cooking, pH changes are used in baking and brewing. Since many reactions in everyday life are affected by pH, it's useful to know how to calculate and measure it.
