Topic content:
In the following reactions, water is neither an oxidant nor a reducer. The redox reaction is ()
A.2Na+2H2O═2NaOH+H2↑
B.2F2+2H2O═4HF+O2
C.2Na2O2+2H2O═4NaOH+O2↑
D.MgO+H2O═Mg(OH)2
Best answer:
A. If the valence of Na element increases and the valence of H element decreases, then water is an oxidant, so A is not selected;
B. If the valence of element F decreases and the valence of element O increases, then water is the reducing agent, so B is not selected;
C. Only the change of the valence of O element in sodium peroxide belongs to redox reaction, and the valence of H and O elements in water remains unchanged, then water is neither an oxidant nor a reducing agent, so C is selected;
D. There is no change in the valence of elements in this reaction, which is not an oxidation-reduction reaction, so D is not selected;
Therefore: C
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)