Topic content:
The following ion equation indicates that the redox reaction is ()
A.HCO3-+OH-=H2O+CO32-
B.H3PO4+3OH-=PO43-+3H2O
C.Fe(OH)3+3H+=Fe3++3H2O
D.3Fe2++4H++NO3-=3Fe3++NO↑+2H2O
Best answer:
A. The valence of elements has not changed, which is not an oxidation-reduction reaction, so A is wrong;
B. It is an acid-base neutralization reaction, not an oxidation-reduction reaction, so B is wrong;
C. It is an acid-base neutralization reaction, and the valence of elements has not changed. It is not an oxidation-reduction reaction, so C is wrong;
D. The valence of Fe and N changes, which belongs to redox reaction, so D is correct
Therefore, D
Answer analysis:
There is no explanation for this question
Test core:
Essence of redox reaction: electron transfer (gain or loss or deviation) Characteristics of redox reaction: valence rise and fall (valence of some elements changes before and after reaction, which is the basis for judging redox reaction)