78

Dilute nitric acid

2019/6/13

The content is: 60%, 65%, 68%, 75%
Dilute nitric acid has strong oxidizing properties:
1 Reaction with metal: metals other than Pt and Au can react with HNO3.
Cu+4HNO3 (concentrated) = Cu(NO3)2+2NO2↑+2H2O [laboratory NO2]
3Cu+8HNO3 (lean)=3Cu(NO3)2+2NO↑+4H2O (laboratory NO, slow reaction at normal temperature, heating reaction is more severe)
Note: a. At room temperature, concentrated HNO3 can passivate metals such as Fe and Al;
The reaction of the metal with nitric acid does not produce H2.
3Cu(s)+8HNO3(aq)--→3Cu(NO3)2(aq)+2NO(g)+4H2O(l)
Fe(s)+4HNO3(aq)--→Fe(NO3)3(aq)+NO(g)+2H2O(l)
3Zn(s)+8HNO3(aq)--→3Zn(NO3)2(aq)+2NO(g)+4H2O(l)
4Zn(s)+10HNO3(aq)--→4Zn(NO3)2(aq)+N2O(g)+5H2O(l)
4Zn(s)+10HNO3(aq)--→4Zn(NO3)2(aq)+NH4NO3(aq)+3H2O(l)

Next

Urea

Previous

Nitric acid