问题 填空题

用如图所示装置(夹持仪器省略)进行实验,将液体A逐滴加入到固体B中,回答下列问题:

(1)图中D装置在实验中的作用是______.

(2)若A为30%H2O2溶液,B为MnO2,C盛有氢硫酸(H2S)饱和溶液,旋开E后,C中出现浅黄色浑浊的现象,写出C中发生反应的化学方程式为______.

(3)若A为浓氨水,B为生石灰,C中盛有AlCl3溶液,旋开E,足够长的时间后,C中的现象是______,C中发生反应的离子方程式为______.

答案

(1)如生成气体极易溶于C中液体,则C中液体上升,因C的球形部分体积较大,当C中液体脱离液面时,由于自身重力作用可回落到C中,从而可起到防止倒吸作用,

故答案为:防倒吸;

(2)氧气和硫化氢发生氧化还原反应可生成硫单质,反应的化学方程式为2H2S+O2=2S↓+2H2O,故答案为:2H2S+O2=2S↓+2H2O;

(3)生石灰与水反应生成氢氧化钙,反应放出大量的热,可使氨气挥发,生成氨气溶于水呈碱性,且一水合氨为弱碱,则与氯化铝反应生成氢氧化铝沉淀,反应的离子方程式为Al3++3NH3•H2O=Al(OH)3↓+3NH4+

故答案为:有白色沉淀生成;Al3++3NH3•H2O=Al(OH)3↓+3NH4+

填空题
阅读理解

C

Jamie Oliver has been invited by Gordon Brown to prepare a banquet at No. 10 for President Barack Obama and other leaders of the G20, offering a cut-price menu to reflect times when trade and industry are far from prosperous and the rate of employment is decreasing.

Downing Street sources say Oliver, the well-known chef, will cook using “honest high-street products” and avoid expensive or “fancy” ingredients (材料).

The prime minister is trying to avoid a repeat of the embarrassment last year when he sat down to an 18-course banquet at a Japanese summit to discuss world food shortages.

Obama, President Nicolas Sarkozy of France, Chancellor Angela Merkel of Germany and other leaders will be served by apprentices (学徒) from Fifteen, the London restaurant Oliver founded to help train young people in poverty in order to make a living by mastering a skill.

Brown wants the dinner to reflect the emphasis of the London summit, which he hopes will lead to an agreement to lift the world out of recession. “To be invited to cook for such an important group of people, who are trying to solve some of the world’s major problems, is really a privilege,” said Oliver.

“I’m hoping the menu I’m working on will show British food and produce is some of the best in the world, but also show we have pioneered a high-quality apprentice scheme at Fifteen London that is giving young people a skill to be proud of.”

The chef has not yet finalized the menu, but is expected to draw inspiration from his latest book, Jamie’s Ministry of Food, which has budget recipes for beef and ale stew (啤酒炖菜) and “impressive” chocolate fudge cake.

49. The underlined word “recession” in Paragraph 5 is closest in meaning to “_______”.

A. business       B. opposition           C. discussion           D. depression

50. What can we learn about Oliver from the text?

A. He is a well-known American cook.        

B. He is invited to attend the G20 summit.

C. He has founded the Fifteen London.      

D. He is one of the apprentices serving leaders of the G20.

51. Which of the following is TRUE according to the text?

A. Oliver is honored to be invited to cook for the G20 leaders.

B. Altogether three presidents are mentioned in the text.

C. President Barack Obama offers the cut-price menu.

D. The menu for the G20 dinner banquet has been decided.

52. What is the Fifteen London?

A. an apartment in London                               B. a luxurious restaurant in London

C. a restaurant as well as a training center                D. a famous avenue