reactions of nitric acid

Reactions of Nitric Acid

Cuprous Oxide, Cu2O reacts with dilute Nitric Acid, HNO3, in the cold to form a solution of Cupric Nitrate, Cu(NO3)2, and Copper, Cu.

Cu2O  +  2 HNO3   ==>   Cu(NO3)2   +   Cu   +   H2O

Cuprous Oxide, Cu2O reacts with concentrated Nitric Acid, HNO3, or with dilute Nitric Acid, HNO3, on heating, when the Cuprous Oxide, Cu2O dissolves with evolution of Nitric Oxide, NO.

3Cu2O + 14HNO3 ==>   6Cu(NO3)2 + 2NO + 7H2O

Dinitrogen Pentoxide, N2O5, is best prepared by dehydrating concentrated Nitric Acid, HNO3, by Phosphorus Pentoxide, P2O5.

2 HNO3   +   P2O5   ==>   N2O5   +   2 HPO3

Nitric Oxide, NO is prepared by the action of Copper, Cu, or Mercury, Hg, on dilute Nitric Acid, HNO3, and was called Nitrous Air.

3 Cu   +   8 HNO3    ==>   3 Cu(NO3)2  +  2 NO  +  4 H2O	

Nitrogen Dioxide, NO2, is a mixed acid anhydride and reacts with water to give a mixture of nitrous and nitric acids.

2 NO2   +   H2   ==>   HNO2   +   HNO3	

If the solution is heated the nitrous acid decomposes to give nitric acid and nitric oxide.

3 HNO2   ==>   HNO3   +   2 NO   +   H2O	

Treatment of silver nitrate with base gives dark grey silver oxide:

2 AgNO3 + 2 NaOH → Ag2O + 2 NaNO3 + H2O