Multiple choice questions:1-5dcbda6-10dcbdc11-15cccc16-20bbdca.

Two. 2 1. Ana+1 N2 H2O

22.( 1)4 (2)3 (3)2 (4) 1

23.ClO2 +4 oxygen, oxidation, nitrogen, helium 24. (1)C, O2, HCl (2)C+CO2 under the condition of arrow, CO (3)CO2+Ca(OH)2 arrow CaCO3+H2O is generated at high temperature.

25. A. Iron shelf B. Long-necked funnel upward air discharge method, the density is greater than air.

(1) Potassium permanganate is heated to generate potassium permanganate+manganese dioxide+oxygen.

(2)B, C (3)B, C C Insert one end of the catheter into the water, cover the hot test tube, and observe whether there are bubbles in the test tube. If there is, the air tightness is good. Is the solubility density smaller or larger than that of air?

26。 White phosphorus reacts with oxygen to generate phosphorus pentoxide (2), which first decreases and then increases B (3) 180 (4), which increases the sealing performance and makes the experimental device more accurate (5) B.

27. (1)180 (2) 6:1:8 (3) 6.7% (4) 2:1(5) w (c) = ar (c) * 6 divided by Mr (c6h. =Ar(C) divided by Mr(CO2)= 12 divided by 44=27.2% m(CO2)=7.2 divided by 27.2% = 26.4g

28.B and C decompose in chemical changes, and the molecular atoms remain unchanged. Mercury oxide is heated to generate oxygen and mercury.