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
Alkali manufacture carried out in a number of factories by an entirely different kind of apparatus. Alkali manufacture Alkali manufacture is the process by which an alkali is made. Typical alkalis, produced commercially, include sodium hydroxide, sodium carbonate, potassium hydroxide and potassium carbonate. A number of processes have been proposed for the manufacture of alkali from various metals, the most common being the Leblanc and ammonia-soda processes. The Leblanc process, which was invented by Nicolas Leblanc around 1790, begins with the decomposition of sodium chloride by sulfuric acid, by which sodium sulfate and hydrochloric acid are produced. The sodium sulfate is afterwards