pH scale

Pure water has the same concentration of hydrogen ions and hydroxide ions; this is represented as 7 (neutral) on a pH scale from 0 to 14.

A substance that increases concentrations of hydrogen ions has a pH lower than 7 and is an acid.

A substance that lowers concentrations of hydrogen ions has a pH greater than 7 and is a base.

An acidic solution has a high concentration of hydrogen ions with a low pH.

A basic (alkaline) solution has a low concentration of hydrogen ions with a high pH.

Quiz