PH PH In chemistry, pH () is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions. More precisely it is the negative of the base 10 logarithm of the activity of the hydrogen ion. At 25 °C, solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. The neutral value of the pH depends on the temperature, being lower than 7 if the
Bohemic acid under neutral or slightly basic pH conditions, and the fats and oils are removed by washing with petroleum ether. Chromatographical separation, in addition to the antibiotics pyrromycin and cinerubin A and B, reveals several individual components of bohemic acid, including alcindoromycin, bohemamine, collinemycin, marcellomycin, mimimycin, musettamycin, rudolphomycin and schaunardimycin. Their names originate from the characters Alcindoro, Colline, Marcello, Mimì, Musetta, Rodolfo (Rudolph) and Schaunard of the Puccini opera "La Bohème", and the acid itself and the bohemamine component carry the name of the opera. The suffix "-mycin" is conventionally added to indicate antibiotics derived from actinobacteria or fungi. The individual