Acid and carbonate
When a carbonate reacts with an acid, it gives off carbon dioxide gas. The products of the reaction between a carbonate and an acid are a salt, carbon dioxide and water. Calcium carbonate is a substance that is naturally found in the shells of a sea creature and snails.
What salt do you think will be produced by the reaction of hydrochloric acid and carbonate?
Hydrochloric acid + calcium carbonate calcium chloride + carbon dioxide + water
Acid and Carbonate word equation:
Acid + Carbonate  water +salt +carbon dioxide
HCl + NaCO  H2O +NaCl + CO2
Acid and Metal
Acids also react with metals to make gas. When an acid reacts with a metal, the gas produced makes a lighted splint go pop. What is this gas? A salt is produced during the reaction.
Hydrochloric acid + calcium  calcium chloride + hydrogen
Choose your reaction
Some metals react violently with acids. Sodium reacts very violently with sulphuric acid.
Sulphuric acid + sodium carbonate  sodium sulphate + carbon dioxide + water
What is acid rain?
Rainwater has a pH of about 5.6, which means that it is naturally slightly acidic. This natural acidity is due to carbon dioxide in the air dissolving into the rain, forming a weak acid called carbonic acid. Rainwater with a lower pH than normal is called acid rain. Burning of fossil fuels in power stations and cars forms pollutants such as sulphur dioxide and nitrogen oxides. These gases dissolve in rainwater to make sulphuric acid and nitric acid, which are strong acids, so also form acid rain.
Effects of acid rain