Why does calcium hydroxide raise soil pH?

1 Answer
Jul 8, 2018

Well its a basic compound after all...

Explanation:

Calcium hydroxide has a chemical formula of #Ca(OH)_2#. The two hydroxide ions are responsible for it being a base. Adding it to soil neutralizes the acid, which turns the #H^+# into water molecules, therefore decreasing their concentration in the process. This therefore increases the #"pH"# of the soil, as #"pH"# is defined by the equation:

#"pH"=-log[H^+]#

where:

  • #[H^+]# is the hydrogen ion concentration in terms of molarity

#"pH"# is inversely proportional to the #H^+# ion concentration. Higher #H^+# concentration means lower #"pH"# and vice-versa.