Fuzhou corrosion recruitment

(3) Preliminary exploration: Because concentrated sulfuric acid and sodium hydroxide have strong corrosiveness, they cannot be used as food desiccants. Because these two substances are very corrosive;

(4) Experimental inquiry: Experiment 1: The preservative must not be quicklime or silica gel. Because the sample is black, quicklime and silica gel are colorless. So fill in: preservatives must not be quicklime and silica gel;

Experiment 2: adding dilute hydrochloric acid into the test tube produces bubbles, which indicates that there is iron powder in the sample. (The solution turns light green, indicating that the solution contains Fe2+; Therefore, the component of preservative is iron powder;

Experiment 3: Carbon monoxide reacts with preservatives to produce carbon dioxide, which makes limewater turbid, indicating that the preservatives have partially deteriorated into iron oxide, so the preservatives contain: iron and iron oxide;

(5) After the complete reaction in Experiment 2, ferrous chloride in light green solution will definitely be generated, and hydrochloric acid may remain; Because the preservative also contains iron oxide, it will generate ferric chloride when it reacts with hydrochloric acid.

So the solute in the solution may be: HClFeCl2 or? HClFeCl2 ferric chloride

(6) The preservation methods that can be adopted are: vacuumizing (or filling the food bag with nitrogen and carbon dioxide, etc. Therefore, filling: vacuumizing (or filling the food bag with nitrogen and carbon dioxide, etc. ).

So the answer is: (3) Preliminary exploration: ① ③ Both concentrated sulfuric acid and sodium hydroxide are corrosive.

(4) experimental inquiry:

The conclusion and explanation of the main phenomena in the experimental operation show that the preservative must not be: ② ⑤ preservative: ④ The substances in the preservative must be Fe and Fe2O3. (5) HCl FeCl 2 or? HClFeCl2 ferric chloride

(6) vacuumizing (or filling the food bag with nitrogen, carbon dioxide, etc.). (just write one)