Aluminium and Iron are rendered passive with concentrated nitric acid.
Explain.
Aluminium and Iron are rendered passive with concentrated nitric acid.
Explain.
When aluminum or iron metals react with nitric acid, then formation of oxides render it passive to further reaction. In all reactions nitric acid acts as strong oxidizing agent.
- Reaction of nitric acid with aluminum:
2Al+HNO3 → 2Al( NO3)3+ H2
Action of concentrated nitric acid render aluminium passive because due to the action of acid corresponding oxides are formed for aluminium it is aluminium oxide which stops or renders further attack of the nitric acid.
- Reaction of iron with nitric acid:
Products of Iron (Fe) reacting with Nitric Acid (HNO3) depends on temperature of reactants as well as concentration of HNO3.
1. With dilute HNO3 Iron gives Ferrous Nitrate [Fe(NO3)2], water and Nitric oxide (NO).
3Fe + 8HNO3 --> 3Fe(NO3)2 + 4H2O + 2NO
2. With concentrated HNO3 iron gives Ferric nitrate [Fe(NO3)3], water and Nitrogen dioxide (NO2).
Fe + 6HNO3 --> Fe(NO3)3 +3H2O + 3NO2
Reaction of iron with concentrated Nitric acid Renders it passive to further reaction due to formation of thin oxide layer on the surface.
When aluminum or iron metals react with nitric acid, then formation of oxides render it passive to further reaction. In all reactions nitric acid acts as strong oxidizing agent.
- Reaction of nitric acid with aluminum:
2Al+HNO3 → 2Al( NO3)3+ H2
Action of concentrated nitric acid render aluminium passive because due to the action of acid corresponding oxides are formed for aluminium it is aluminium oxide which stops or renders further attack of the nitric acid.
- Reaction of iron with nitric acid:
Products of Iron (Fe) reacting with Nitric Acid (HNO3) depends on temperature of reactants as well as concentration of HNO3.
1. With dilute HNO3 Iron gives Ferrous Nitrate [Fe(NO3)2], water and Nitric oxide (NO).
3Fe + 8HNO3 --> 3Fe(NO3)2 + 4H2O + 2NO
2. With concentrated HNO3 iron gives Ferric nitrate [Fe(NO3)3], water and Nitrogen dioxide (NO2).
Fe + 6HNO3 --> Fe(NO3)3 +3H2O + 3NO2
Reaction of iron with concentrated Nitric acid Renders it passive to further reaction due to formation of thin oxide layer on the surface.
