PH the Hammett acidity function, "H", has been developed in connection with superacids. The concept of "unified pH scale" has been developed on the basis of the absolute chemical potential of the proton. This model uses the Lewis acid–base definition. This scale applies to liquids, gases and even solids. In 2010, a new "unified absolute pH scale" has been proposed that would allow various pH ranges across different solutions to use a common proton reference standard. Pure water is neutral. When an acid is dissolved in water, the pH will be less than 7 (25 °C). When a base, or alkali,
Fecal pH test Fecal pH test A fecal pH test is one where a specimen of feces is tested for acidity in order to diagnose a medical condition. Human feces is normally acidic. An acidic stool can indicate a digestive problem such as lactose intolerance or a contagion such as "E. coli" or rotavirus, or overgrowth of the acid producing bacteria (such as lactic acid bacteria for instance). The average pH for a healthy person is a pH of 6.6. The test is fast and can be performed in a doctor's office. A patient must not be receiving antibiotics. At least half a