题干

某化学兴趣小组的同学为制取少量溴乙烷,查阅资料得知:
NaBr+H2SO4→HBr+NaHSO4
CH3CH2OH+HBr  CH3CH2Br+H2O
化学兴趣小组根据实验原理设计如图的装置.
根据题意完成下列填空:有关数据列表如下:
乙醇
溴乙烷
状态
无色液体
无色液体
密度/g•cm3
0.8
1.4
沸点/℃
78.5
119.0
熔点/℃
﹣l30
38.4
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同类题4

阅读短文,按要求完成各题。

    I was ten when I first sat with my grandmother behind the cashier(收银台)in her general store.____ I quickly learned the importance of treating customers politely and saying “thank you.”

    At first I was paid in candy.____ I worked every day after school, and during the summer and on weekends and holidays from 8 a.m. to 7 p.m. My father helped me set up a bank account.____ 

    By the time I was 12, my grandmother thought I had done such a good job that she promoted me to selling cosmetics(化妆品). I developed the ability to look customers directly in the eye. Even though I was just a kid, women would ask me such things as “ What color do you think I should wear?” I took a real interest in their questions and was able to translate what they wanted into makeup(化妆)ideas.____

    The job taught me a valuable lesson: to be a successful salesperson, you didn't need to be a Rocket scientist—you needed to be a great listener.____ Except they are no longer women purchasing cosmetics from me; instead, they are kids who tell me which toys they would like to see designed and developed.

A. Later I received 50 cents an hour.

B. Before long, she let me sit there by myself.

C. I ended up selling a record amount of cosmetics.

D. Today I still carry that lesson with me: I listen to customers.

E. My grandma's trust taught me how to handle responsibility.

F. Soon I found myself looking more beautiful than ever before.

G. Watching my money grow was more rewarding than anything I could have bought.

同类题5

阅读材料,完成下列要求。

材料一:明朝中后期至19世纪中叶以前,苏州是中国唯一拥有全国经济中心地位的城市。苏州“首重机业,城东比户皆然”,丝绸、棉布行销全国各省,“其外洋如高丽、印度以及欧美各国,莫不有销路”。鸦片战争之后,“洋布盛行,布市销减”,“蚕棉得丰岁,而皆不偿本”。据统计,道光年间苏州尚有12000余部织机,到1880年织机仅有5800部。苏州的手工业行会众多,许多行会在19世纪七八十年代还对产品划定统一的价格,并实施统一工价,以限制竞争和自由雇佣。棉布、棉纱、茶丝和米的贸易都不再经流苏州,转而经由上海。20世纪二三十年代,苏州变成了大上海的“卫星城”。

──摘编自王卫平《明清时期江南城市史研究》

材料二:17世纪,曼切斯特是一个小镇。18世纪60年代起,随着纺纱业和织布业的机械化,成为英国工业革命的摇篮。1760年,开通了通向附近煤区沃斯利的英国第一条运河,1830年又建成通向重要港口利物浦的铁路,率先实现了交通运输革命。在此期间城市经济和人口高速增长。18世纪20年代,它的人口仅12000,1841年底猛增至40万人,跻身于全国大城市之列。1848年,沿曼切斯特向外延伸的公路把附近的奥尔德姆、海德等城镇链接起来,使整个集合体的人口达到106.3万人。

──摘编自王章辉《近代英国城市化初探》