PH is dissolved in water, the pH will be greater than 7. A solution of a strong acid, such as hydrochloric acid, at concentration 1 mol dm has a pH of 0. A solution of a strong alkali, such as sodium hydroxide, at concentration 1 mol dm, has a pH of 14. Thus, measured pH values will lie mostly in the range 0 to 14, though negative pH values and values above 14 are entirely possible. Since pH is a logarithmic scale, a difference of one pH unit is equivalent to a tenfold difference in hydrogen ion concentration. <br> The pH
Alkali hydroxide Alkali hydroxide The alkali hydroxides are a class of chemical compounds which are composed of an alkali metal cation and the hydroxide anion (OH). The alkali hydroxides are: The most common alkali hydroxide is sodium hydroxide, which is readily available in most hardware stores in products such as a drain cleaner. Another common alkali hydroxide is potassium hydroxide. This is available as a solution used for cleaning terraces and other areas made out of wood. All alkali hydroxides are very corrosive, being strongly alkaline. A typical school demonstration demonstrates what happens when a piece of an alkali metal is introduced