The insoluble reactant chosen depends upon the particular salt required.
As the reaction between metals and acids produces flammable 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 ions in the acids with metal ions or ammonium ions.
A salt and hydrogen are produced when acids react with metals. In general:
acid + metal salt + hydrogen
hydrochloric acid + magnesium magnesium chloride + hydrogen
2HCl(aq) + Mg(s) MgCl2(aq) + H2(g)
Hydrogen is collected in a test tube during the reaction between magnesium and hydrochloric acid. Describe the laboratory test for hydrogen.
Put a lighted splint near the mouth of the test tube. Hydrogen ignites with a squeaky pop.
A salt, water and carbon dioxide are produced when acids react with carbonates. In general:
acid + carbonate salt + water + carbon dioxide
hydrochloric acid + copper carbonate copper chloride + water + carbon dioxide
2HCl(aq) + CuCO3(s) CuCl2(aq) + H2O(g) + CO2(g)
Carbon dioxide is given off during the reaction between copper carbonate and hydrochloric acid. Describe the laboratory test for carbon dioxide.
Bubble the gas through limewater. Carbon dioxide turns limewater milky or cloudy white.