Multiprotism

Hydrogen ions are quite often referred to as protons, because that is all that is left of a hydrogen atom when its electron has been removed from it. Some acids have the capability of providing more than one hydrogen ion from each molecule. Such acids are called multiprotic.

If an acid has more than one proton, it is called multiprotic. Sulfuric acid, which has the formula H₂SO₄, has two hydrogen ions which can dissociate from the molecule. It is called diprotic because it has two protons which can dissociate. There are a number of other acids that can dissociate to give two or even three protons. Those that give three protons are called triprotic.

Bases that contain more than one hydroxide ion in their formula are called multibasic. Magnesium hydroxide is called dibasic because it has two hydroxide ions that can dissociate from each magnesium. There are several other dibasic bases. There are even a few tribasic bases that dissociate to give three hydroxide ions.

Practice (Ex. 14)

For practice, use the Arrhenius concept to write equations showing the dissociation of these acids and bases (which are also listed in exercise 14 in your workbook.) Check your answers below, then continue.

Answers (Ex. 14)

Here are the answers to exercise 14.

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