2020年9月30日 · The pH scale shows how acidic or basic a chemical is in aqueous solution (mixed with water). The scale runs from 0 (most acidic) to 14 (most alkaline or basic), where 7 is neutral pH. Chemicals with pH values from 0 up to 7 are acids, those with a pH value of 7 are neutral, and those with pH values greater than 7 up to 14 are bases. Here is a ...

Lemon juice tastes sour because it contains 5% to 6% citric acid and has a pH of 2.2 (high acidity). Plants contain pH-dependent pigments that can be used as pH indicators, such as those found in hibiscus, red cabbage (anthocyanin), and grapes .

2023年1月30日 · The pH range does not have an upper nor lower bound, since as defined above, the pH is an indication of concentration of H +. For example, at a pH of zero the hydronium ion concentration is one molar, while at pH 14 the hydroxide ion concentration is one molar.

2018年1月7日 · The pH calculator can determine the pH from H⁺ molar concentration, or Ka, and the concentration of a solution.