(40 big? Zunyi) In the following figure, Figure A is a kind of "chemical oxygen self-rescuer", which is mainly used for self-rescue of coal mine emergency and anoxic patients. it

(u) According to the law of conservation of mass, in a chemical reaction, the types of atoms do not change before and after the reaction, and the number does not increase or decrease. The chemical equation of the reaction is:

You KO0+0CO0=0X+3O0, you have k, u0 o, 0 c before the reaction, and you have u o after the reaction, so it can be inferred that the chemical formula of X is K0C03；;

(0) According to the laboratory, the solid heating generator is used to make oxygen with potassium permanganate, so the generator is selected as B;

According to the oxygen density ratio in the air is 3 and it is insoluble in water, the collection device is: e or g;

Follow the steps of writing chemical equations: write notes, etc. The chemical equation of making oxygen with potassium permanganate is: 0K, n0, and you? △? . ? K0 port n0+ port n00+00 write;

(3) The hydrogen peroxide and manganese dioxide oxygen generator used in the laboratory is of solid-liquid normal temperature type. According to the separating funnel, the dropping speed can be controlled by the piston, so that the reaction rate can be increased, the medicine can be saved, and the reaction can be started and stopped at any time. Therefore, Chen Xiao is considered a better choice.

According to the steps of writing chemical equations, such as writing and dispensing, the reaction equation of making oxygen with hydrogen peroxide and manganese dioxide in the laboratory is as follows:

0H000？ Mouth nO0? . ? 0h 00+00↑；

So the answer is: (u)1k0c03;

(0)①B； ? 20K, no, what about you? △? . ? K0 port n0+ port n00+00 write; (3) e or G (give points for answering a question correctly)

(3)① In the early morning, controlling the reaction rate (or saving drugs) can make the reaction happen at any time and stop at any time. Give points if you answer one correctly);

②0H000？ Mouth nO0? . ? 0H00+00↑。