What Minerals Make Alkaline PH?
When an acid neutralizes a base, an ionic compound called a salt is formed. Salts, some commonly known as minerals, can form solutions that can be neutral, acidic, or basic (also known as alkaline), depending on the acid-base properties of the constituent cations (positive ions) and anions (negative ions).
Other People Are Reading
-
Relative Strengths of Acids and Bases
-
Before a rule can be established about which salts (or minerals) produce an alkaline pH, we need to understand something about the relative strengths of acids and bases. A strong acid is one that nearly completely dissociates in water, creating a very acidic pH. A weak acid is one that only slightly dissociates in water, leaving a slightly acidic pH. The same goes with strong and weak bases.
Generality of Acid-Base Properties of Salts
-
As a general rule, salts formed by the reaction of a strong acid with a strong base are neutral, salts formed by the reaction of a strong acid with a weak base are acidic, and salts formed by the reaction of a weak acid with a strong base are basic. It's the influence of the stronger partner that dominates.
-
pH Scale
-
The pH scale is used to generate numbers that we can easily associate with acidic, basic, and neutral solutions. The range of pH values <7 is considered acidic. A pH of 7 is neutral. A basic (or alkaline) solution will have a pH range of >7.
Common Ion Effect
-
The shift in the position of an equilibrium upon the addition of a substance that provides an ion in common with one of the ions already involved in the equilibrium is known as the common ion effect. This concept can account for tricky equilibria equations within the solution, which contribute to the pH. This means that it is not always the amount of mineral that you add to the solution that changes the pH.
Salts That Yield Alkaline pH
-
Salts derived from a strong base and a weak acid can yield basic solutions. Common examples of mineral-derived ions that yield alkaline pH are cyanide (CN-), nitrate (NO2-), fluoride (F-), acetate (CH3CO2-), and carbonate (CO3-2). This means that any mineral that contains one of these constituent ions when dissolved will produce an alkaline pH. The minerals that can do this are far too numerous to name. See the link in the resources for minerals listed by their constituent ions.
-
References
Resources
- Photo Credit Image by Flickr.com, courtesy of Kelbv
