Understand pH, acids and bases

pH means potential of hydrogen. It is the measure used to determine if a solution is either acid or alkaline.

A solution can be anything fluid such as our body fluids (blood, urine, saliva...) or a beverage (coffee, tea, wine, water...).

The pH scale goes from 0 to 14 with neutral being 7.
The scale is acid from 0 to 7 and alkaline from 7 to 14.

An acid is a molecule or an ion* that can contribute a hydronium ion (H+) to a solution. An acid has the power to neutralize alkalis.

An alkali (which is often called a "base") is a molecule or an ion that combines with hydronium ions to remove them from a solution.

* An ion is an atom that carries a positive or a negative electric charge.

To simplify, in our body we have the acid ions H+ (hydronium) and the alkali ions HCO3- (bicarbonate). They neutralize each other and our body's goal is to keep the balance between those two ions.

Here are a few pHs:
Stomach's pH = 2
Small intestine's pH = 6
Large intestine's pH around 8
Our blood's pH is between 7.32 and 7.42.


Realized by Laurence LIVERNAIS-SAETTEL, dietetian
© Copyright L. Livernais-Saettel 2000
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