Reactions of acids
acidSubstance producing more hydrogen ions than hydroxide ions when dissolved in water. take part in reactions in which saltThe substance formed when the hydrogen ion in an acid is replaced by a metal ion. are produced. In these reactions, the salt is formed by replacing the hydrogen ionElectrically charged particle, formed when an atom or molecule gains or loses electrons. in the acids with metal ions or ammonium ions.
Reactions with metals
A salt and hydrogen are produced when acids react with metalShiny element that is a good conductor of electricity and heat, and which forms basic oxides..
In general:
acid + metal → salt + hydrogen
For example:
hydrochloric acid + magnesium → magnesium chloride + hydrogen
2HCl(aq) + Mg(s) → 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.
Put a lighted splint near the mouth of the test tube. Hydrogen ignites with a squeaky pop.
Reactions with metal oxides
A salt and water are produced when acids react with metal oxideCompound containing oxygen or oxide ions.. Metal oxides are baseA substance that reacts with an acid to neutralise it and produce a salt., because they neutralise acids.
In general:
acid + metal oxide → salt + water
For example:
sulfuric acid + copper oxide → copper sulfate + water
H2SO4(aq) + CuO(s) → CuSO4(aq) + H2O(l)
Reactions with metal hydroxides
A salt and water are produced when acids react with metal hydroxides. Metal hydroxides are bases because they neutralise acids.
In general:
acid + metal hydroxide → salt + water
For example:
nitric acid + sodium hydroxide → sodium nitrate + water
HNO3(aq) + NaOH(s) → NaNO3(aq) + H2O(l)
Reactions with carbonates
A salt, water and carbon dioxide are produced when acids react with carbonates.
In general:
acid + carbonate → salt + water + carbon dioxide
For example:
hydrochloric acid + copper carbonate → copper chloride + water + carbon dioxide
2HCl(aq) + CuCO3(s) → CuCl2(aq) + H2O(l) + CO2(g)
Question
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 limewaterCalcium hydroxide solution. It turns milky in the presence of carbon dioxide.. Carbon dioxide turns limewater milky or cloudy white.