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What useful products can be made from acids? - OCR 21st CenturyMaking salts from metals and metal compounds

Many products require ingredients made by the reaction of acids. These include cleaning products and food additives. Acids are used on an industrial scale to produce chemicals such as fertilisers.

Part of Combined ScienceMaking useful chemicals

Making salts from metals and metal compounds

A can be prepared by reacting an with a suitable including:

  • a
  • a carbonate

The insoluble reactant chosen depends upon the particular salt required.

As the reaction between metals and acids produces hydrogen, chemists usually make salts by reacting a metal compound such as a metal carbonate with an acid.

Acids take part in reactions in which salts are produced. In these reactions, the salt is formed by replacing the hydrogen in the acids with metal ions or ammonium ions.

Learn more on salt formation in this podcast.

Reactions with metals

A salt and hydrogen are produced when acids react with metals. In general:

acid + metal \(\rightarrow\) salt + hydrogen

For example:

hydrochloric acid + magnesium \(\rightarrow\) magnesium chloride + hydrogen

2HCl(aq) + Mg(s) \(\rightarrow\) MgCl2(aq) + H2(g)

Question

Hydrogen is collected in a test tube during the reaction between magnesium and hydrochloric acid. Describe the laboratory test for hydrogen.

Reactions with carbonates

A salt, water and carbon dioxide are produced when acids react with carbonates. In general:

acid + carbonate \(\rightarrow\) salt + water + carbon dioxide

For example:

hydrochloric acid + copper carbonate \(\rightarrow\) copper chloride + water + carbon dioxide

2HCl(aq) + CuCO3(s) \(\rightarrow\) CuCl2(aq) + H2O(g) + CO2(g)

Question

Carbon dioxide is given off during the reaction between copper carbonate and hydrochloric acid. Describe the laboratory test for carbon dioxide.