It can be made by the neutralization of Nitric Acid (HNO₃).

HNO3 (aq)+NaOH(aq)→NaNO3 (aq)+H2O(l)

NOTE:

• All nitrates are soluble in water.

• Thermal decomposition of nitrates.

• Nitrates of group 1. Eg: NaNo₃ and KNO₃ decompose on heating to give nitrite and oxygen.

2NaNO3 (s)→2NaNO2 (aq)+O2 (g)

• Nitrates of group 2. Eg: Mg(NO₃)₂ and nitrates of copper (Cu), zinc (Zn), lead (Pb) decompose on heating to their corresponding oxide, nitrogen dioxide (NO₂) and oxygen.

Zn(NO3)2 (s)→ZnO(s)+NO2 (g)+O2 (g)

• The nitrates of silver and mercury decompose on heating to the metal nitrogen dioxide and oxygen because the metal oxides are unstable to heat which is usually grey.

2AgNO3 (s)→2Ag(s)+NO2 (g)+O2 (g)

Test for Nitrates (NO₃)

A solution of the salt is made in a test tube. Iron II sulphate solution is added to it. Concentrated sulphuric acid (H₂SO₄) is added gently at the side of the test tube. If a brown ring is formed, the salt is a nitrate.

Uses of Nitrates

6. Nitrates are used as fertilizers. Eg: Ammonium nitrate (NH₄NO₃), NANO₃, KNO₃.
6. Sodium nitrate is used to make gun powder (explosives).
6. Used in making dyes.