问题 实验题

试回答下列问题:

⑴指出下列实验用品或仪器(已洗涤干净)使用时的第一步操作:

①石蕊试纸(检验气体性质)                                                       

②容量瓶                                                                       

(2)下列实验中所选用的仪器或操作以及结论合理的是____________。

A.用托盘天平称量5.85 g氯化钠晶体

B.仅用蒸馏水和pH试纸,就可以鉴别pH相等的H2SO4溶液和CH3COOH溶液

C.用碱式滴定管量取25.00 mL高锰酸钾溶液

D.不宜用瓷坩埚灼烧氢氧化钠、碳酸钠E. 量筒内液体体积读数为10.0 mL时,全部倒入烧杯内的实际体积也是10.0 mL

F. 100 mL容量瓶内液面正好达到刻度线时,全部倒入烧杯内的实际体积也必为100 mL

(3)欲量取15.00 mL Na2CO3溶液,应选用的仪器是_________________。

(4)在硫酸铜晶体里结晶水含量的测定实验中,称量操作至少要进行___________次。

答案

⑴①将石蕊试纸润湿   ②检验容量瓶是否漏水(2)B D E  (3)碱式滴定管  (4) 4

单项选择题
阅读理解

Mrs. Allen’s husband died ten years ago when her son and daughter were still in high school. Mr. Allen had left some money, and since Mrs. Allen had managed a bookstore before she was married, she took the money and bought a shop in town. Later she moved the shop out to the shopping center.

She was a pleasant woman; she worked hard and was well-informed about books, and so the bookstore prospered(生意兴隆) and she was able to hire a friend to help her.

Laura Barnes, Mrs. Allen’s friend and assistant, was also a widow. She had some free time and the need for a little extra-money, and so she took the job in the bookstore. She was too clever and friendly, and the two women were well-known in the neighbourhood as “Mrs. A” and “Mrs. B”

41. How many people in all were there in the two women’s families? ______.

A. At least 8       B. At least 7       C. At least 6       D. At least 4

42. The bookstore prospered ______.

A. after Mrs. Allen lost control of it

B. before Mrs. A got to know Mrs. B

C. because the two women had little housework to do

D. because Mrs. A became expert at management and threw herself into it

43. Why did Mrs. A hire Mrs. B? ______.

A. Mrs. B asked for very little pay

B. She believed that Mrs. B was the very person to help her to improve management

C. Mrs. B was a friend of hers

D. She was also that kind of woman like her

44. Which of the following is true? ______.

A. Mrs. A set up her bookshop in the shopping center

B. Mr. Allen was dead but Mr. Barnes alive

C. Mrs. A managed to set another bookstore with Mrs. B

D. The two children of Mrs. A were of the same age