问题 选择题

下列有关实验的说法正确的是

A.除去氧化铁中混有的少量氧化铝,可加入过量的氢氧化钠溶液,完全反应后,过滤

B.为测定熔融氢氧化钠的导电性,可在瓷坩埚中熔化氢氧化钠固体后进行测量

C.制备Fe(OH)3胶体,通常是将Fe(OH)3固体溶于热水中

D.可用澄清石灰水鉴别Na2CO3溶液和NaHCO3溶液

答案

答案:A

A.正确

B.瓷坩埚中的二氧化硅可与氢氧化钠反应:SiO2+2NaOH=Na2SiO3+H2O,排除

C.制备Fe(OH)3胶体,通常是:在沸水中逐滴滴加饱和的FeCl3溶液,继续煮沸至溶液呈红褐色,即停止加热即可,排除

D.澄清石灰水与Na2CO3溶液和NaHCO3溶液均反应产生白色沉淀碳酸钙,排除

故答案为A

选择题
阅读理解

My friends, Emma Daniels, spent the summer of 1974 traveling in Israel. During her monthlong stay in Jerusalem she often went to a café called Chocolate Soup. It was run by two men, one of whom – Alex – used to live in Montreal. One morning when Emma went in for coffee, while chatting with her new friend Alex, she mentioned that she had just finished the book she was reading and had nothing else to read. Alex said he had a wonderful book she might like, and that he’d be happy to lend it to her. As he lived just above the café, he quickly ran up to get it. The book he handed to Emma just minutes later was Markings, a book by a former Secrectary-General of the United Nations (UN).

Emma had never read it, nor had she ever bought a copy. But, when she opened it up, she was floored to see her own name and address inside the cover in her own handwriting(笔迹).It turned out that the summer before, at a concert back in Montreal, Emma had met a Californian who was in town visiting friends. They decided to exchange(交换)addresses, but neither of them had any paper. The man opened up a book he was carrying in his backpack(背包) and asked Emma to write her name and address inside. When he returned to California, he left the book behind in Montreal, and his friend   Alex kept it. When Alex later moved to Jerusalcm, he took the book along.

41. Alex lent Emma the book, Markings,           .

A. to show his friendliness to her                  B. to show his interest in reading

C. to tell her about the importance of UN              D. to let her write her name and address inside

42. How did Emma feel the moment she opened the book?

A. Pleased.                         B. Satisfied.             C. Worried.                         D. Surprised.

43. We can learn from the text the Californian             .

A. met Emma at a concert                                   B. invited Emma to a concert

C. introduced Emma to his friend                  D. left Emma his backpack

44. Who was supposed to be the first owner of the book?

A. An official of the UN.                             B. A coffee shop owner.

C. A friend of the author’s.                                  D. Alex’s friend form California.