GCSE SCIENCE CHEMISTRY HIGH SCHOOL - Making Salts - Acid - Base

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Salts made from an acid and a base.

Metal oxides are bases. A base will neutralise an acid.
If the metal oxide dissolves in water
it will form hydroxide ions and is called an alkali.

Any chloride or sulfate can be safely made
by reacting the appropriate metal oxide
with hydrochloric acid to make the chloride
or sulfuric acid to make the sulfate.

For example

sulfuric acid + iron(II) oxide iron(II) sulfate + water
H₂SO₄_(aq) + FeO_(s) FeSO₄_(aq) + H₂O_(l)

hydrochloric acid + copper(II) oxide copper(II) chloride + water
2HCl_(aq) + CuO_(s) CuCl₂_(aq) + H₂O_(l)

The base can be added a little at a time to the acid
and it will dissolve to form the soluble salt.
When no more base dissolves, the acid has been neutralised.
The undissolved base can be removed from the solution by filtration.
Pure salt crystals can then be crystallised from the neutral solution.

You can also use a carbonate to make salts in the same way.

Headings Acids and Alkalis Search Questions

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