PH temperature increases. Pure water is neutral, pH 7 at (25 °C), being neither an acid nor a base. Contrary to popular belief, the pH value can be less than 0 or greater than 14 for very strong acids and bases respectively. Measurements of pH are important in agronomy, medicine, chemistry, water treatment, and many other applications. The pH scale is traceable to a set of standard solutions whose pH is established by international agreement. Primary pH standard values are determined using a concentration cell with transference, by measuring the potential difference between a hydrogen electrode and a standard electrode such
Casein paint or varnished for a gloss finish. The binder for casein paint is made by dissolving casein in an alkali, usually lime, ammonium carbonate, or borax. Casein itself is precipitated from milk by the action of an acid or the enzyme rennet. Lime casein works well on porous surfaces, even outdoors, though it has a short shelf-life and must be used with pigments that are balanced against the binder's low pH. Ammonium carbonate casein has similar strengths and weaknesses. Borax casein has a shelf-life of several weeks, is pH neutral, and can be used outdoors through the addition of linseed oil.