Dry ammonium sulphate is made when concentrated sulphuric acid is sprayed into a container filled with ammonia gas. It is also prepared from gypsum by adding gypsum in powdered form to a solution of ammonium carbonate. The molecular formula of ammonium sulphate is (NH4)2SO4.
Ammonium sulphate is a white crystalline odorless salt. It is widely used as a fertilizer as it contains 24 percent sulphur and 21 percent nitrogen, which makes it good for increasing the fertility of the soil. It makes the soil alkaline by lowering its pH value. It is also used as a food additive and in the preparation of other salts of ammonium.
Ammonium sulphate readily dissolves in water but not in organic solvents such as alcohol, acetone and ether. At 0 degrees Celsius, about 70.6 grams of ammonium sulphate dissolves in 100 milliliters of water. The molar mass of ammonium sulphate is 132.14 grams per mole. When heated, it decomposes at 235 to 280 degrees Celsius. The density of ammonium sulphate is 1.769 grams per cubic centimeter at 20 degrees Celsius. The compound is commonly referred to as diammonium sulphate or sulphuric acid diammonium salt, depending on the specific use for which it is being used.