(b) A second example would be magnesium oxide dissolved in water.
MgOH+ + OH -
MgO + H2O <---------
By accepting a proton from water, magnesium oxide has likewise increased the
concentration of hydroxyl ions in the solution.
The two theories explain all the properties of acids and bases that will be
utilized in medicine. It deserves mention that there are other theories of acids
and bases that explain more complex phenomena. If these are of interest to
you, a college chemistry text should have a discussion of some of them.
c. Properties of Acids. We have defined all acids based on one common
property, the ability to donate hydrogen ions in solution. Therefore, you should expect
them all to exhibit a set of common properties, which they do. The properties we are
concerned with are as follows:
(1) Acids change blue litmus paper to red. Litmus paper, which contains
dyes sensitive to hydrogen ion concentration, turns red when there is a high
concentration, blue when there is a low concentration.
(2) Acids have a sour taste. This property is familiar to you if you have ever
tasted a lemon. Lemons contain citric acid, which gives them their sour taste.
Acids react with metals to release hydrogen gas. For example:
Zn + 2H+ ------> Zn ++ + H2
You will notice that this reaction is an oxidation-reduction reaction. For practice, pick
out the oxidizing and reducing agents.
(4) Acids react with carbonates and bicarbonates to form carbon dioxide.
CaCO3 + 2HCl ------> CaCl2 + H2O + CO2 ↑
(5) Acids react with bases to form salts and water (neutralization reaction).
HCl + NaOH -------> NaCl + H2O