(20 12? A new ceramic aluminum nitride: Al2O3+3C+N can be prepared by reducing Al2O3 at high temperature. 2AlN+3CO is prepared by this method.

(1) The solid materials used for raw materials are alumina, carbon and aluminum nitride, so the impurities in aluminum nitride can only be alumina and carbon. According to the topic information, when AlN is dissolved in a strong alkali solution, NH3 will be generated. The chemical equation is: AlN+NaOH+H2O=NaAlO2+NH3↑, so the answer is: alumina and carbon; AlN+NaOH+H2O = NAA lo 2+NH3↑；

(2) Alkaline lime is used to dry ammonia. In the device, the long-necked funnel can prevent backward suction, so the answer is: alkali lime; Prevent back suction;

(3) Ammonia production is the key to the accuracy of experimental data. In order to ensure that all ammonia produced is discharged and absorbed by sulfuric acid, the answers are: nitrogen can discharge all ammonia and be absorbed by sulfuric acid;

(4) A. The oxygen in the device will not affect the amount of ammonia, so the oxygen in the device will be exhausted before adding NaOH solution, which has nothing to do with the test accuracy, so A is correct;

B. The NaOH solution should not be dropped too quickly, so that the aluminum nitride can fully react with sodium hydroxide to release ammonia gas. The amount of ammonia is related to the accuracy of the experiment, so B is wrong;

C. Cancel device B, ammonia and water vapor will be absorbed by concentrated sulfuric acid, which will make the result higher and affect the accuracy of the result, so C is correct;

Adding a drying pipe filled with alkali lime after D.C can prevent the interference of water vapor in the air and improve the accuracy, so D is wrong;

So, choose AC;

(5) Before and after the experiment, the average weight gain of device C was ng, that is, the mass of ammonia produced was ng, and nitrogen atoms were conserved. The amount of ammonia is equal to that of AlN, and the mass fraction of AlN is n17mol× 41g/mol = 41n17m, so the answer is: 465438+.

(6) If the purity of AlN measured is high, the measured value of ammonia gas is high. It may be that the concentrated sulfuric acid in device C absorbed the water vapor in the air, so the answer is that the concentrated sulfuric acid in device C absorbed the water vapor in the air.