化学题目及答案（Chemical questions and answers）.doc

化学题目及答案（Chemical questions and answers） The gao ii institute exam question One. Choice question (50 points, only one correct answer for each question) Of the following substances, they are pure A. alkali lime b. raw lime c. gasoline d. alumina 2. The isotopes of each of the following groups are A. protium and deuterium B. Alum and c. diamond and graphite d. butane and isobutane When the laboratory takes the following gases, it is only collected by drainage method A.c. H4 B.C., O2 C.N O D.N 4. In nature, there are elements that exist both in the form of verbiage and in the form of combination A. c l B.C.S. d. Na 5. Under normal temperature, the iron plate is put into the following solution, which can be observed clearly A. concentrated sulfuric acid b. dilute sulphuric acid C. ZnSO4 solution The following substances are exposed in the air, and no chemical changes occur A. white phosphorus b. hydrogen sulfate c. caustic soda solution d. sodium nitrate solution 7. To remove a small amount of aluminum powder mixed with iron powder, the reagent used should be selected A. dilute hydrochloric acid b. nitric acid c. ammonia. D. sodium hydroxide solution 8. If acetaldehyde is transformed into bromoethane by the following two steps: These two steps are respectively in the organic reaction type A. The polymerization and hydrolysis reaction b. elimination of reactions and addition reactions C. The substitution reaction of addition reaction D When the following substances are solid, the crystal type is the same A.S iO2 and CO2 b.acl and HCl ci. 2 and diamond D.N H3 and H2O 10. The following gas can be passed into the water to produce both oxyacid and anoxic acid A. chlorine b. gas nitrous oxide The following statements about alkali metals are incorrect A. Potassium has more gold than sodium, and potassium and sodium are purple and yellow respectively C. Alkali metals can react with water to produce hydroxide and release hydrogen The melting point of alkali metals increases with