Topic content:
In the following reactions, sulfur element shows oxidizability ()
A. Reaction of dilute sulfuric acid with zinc particles
B. Reaction of sulfur dioxide with oxygen
C. Concentrated sulfuric acid reacts with carbon
D. Sulfur trioxide reacts with water
Best answer:
A、 Dilute sulfuric acid reacts with zinc particles to generate zinc sulfate and hydrogen, and the valence of sulfur element remains unchanged, so the sulfur element does not show oxidation, so A is wrong;
B、 When sulfur dioxide reacts with oxygen, it will generate sulfur trioxide. The valence of sulfur element increases, and sulfur element shows reducibility, so B is wrong;
C、 Concentrated sulfuric acid reacts with carbon to generate sulfur dioxide, carbon dioxide and water. The valence of sulfur element decreases, so sulfur element shows oxidation, so C is correct;
D、 Sulfur trioxide reacts with water to generate sulfuric acid, and the valence of sulfur element remains unchanged, so sulfur element does not show oxidation, so D is wrong
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)