10. The device for preparing metal W by reducing WO3 with H2 in the laboratory is shown in the figure (Zn particles often contain impurities such as carbon, and a small amount of oxygen is absorbed by pyrogallic acid solution). The following statement is correct (D).
A.①, ② and ③ are filled with potassium permanganate solution, concentrated sulfuric acid and pyrogallic acid solution in turn.
B. Before heating the tube furnace, collect the gas at ④ with a test tube and ignite it, and judge the gas concentration by sound.
C, when the reaction is completed, first close the piston k, and then stop heating.
D device q (kipper generator) can also be used to prepare oxygen by reacting manganese dioxide with concentrated hydrochloric acid.
1 1. In order to cooperate with the anti-corrosion technology of port wharf foundation, impressed current cathodic protection is usually used for anti-corrosion, and the working principle is shown in the figure, in which high-silicon cast iron is an inert auxiliary anode. The following statement is incorrect (c)
A, introducing protective current to make the corrosion current on the surface of steel pipe pile close to zero.
B after electrifying, the external circuit electrons are forced to flow from high silicon cast iron to steel pipe piles.
C high silicon cast iron is used as a loss anode material to transmit current.
D the protection current should be adjusted according to the change of environmental conditions.
12. The number of atoms of short-period main group elements W, X, Y and Z increases in turn. The simple hydride of W can be used as refrigerant, and the atomic radius of Y is the largest among all short-period main group elements. The salt formed by X, Y and Z elements is dissolved in water, and diluted hydrochloric acid is added to precipitate yellow precipitate, resulting in irritating gas. The following statement is incorrect (c)
The thermal stability of A.X simple hydride is stronger than that of W.
Simple ions B.Y and x have the same electron shell structure.
The aqueous solution of compound formed by C, Y and Z can make blue litmus test paper turn red.
D.z and x belong to the same main family, and y belongs to the same period.
The above are some questions and answers of a comprehensive science examination paper in the national college entrance examination for reference only.