您所在的当前位置：高中化学试题 >

物质的分离、提纯

> 关于纸层析法分离铁离子和铜离子的实验，下列说法正确的是 [ ] A．采用滤纸作固定相，用9ml丙酮与lmL 6mol·L -1盐酸配成的混合溶液作展开剂 B．应沿试管壁小心将展开剂慢慢倒入试管底部 C．层析时样点浸入展开剂中 D．配制试样溶液浓度较大，点样时试样斑点较小

问题：

发布时间：2024-09-11

关于纸层析法分离铁离子和铜离子的实验，下列说法正确的是
[ ]
A．采用滤纸作固定相，用9ml丙酮与lmL 6mol·L ^-1盐酸配成的混合溶液作展开剂
B．应沿试管壁小心将展开剂慢慢倒入试管底部
C．层析时样点浸入展开剂中
D．配制试样溶液浓度较大，点样时试样斑点较小

参考答案：

提问用户：d4***gnc

可能感兴趣的题目：

1 Uncle Wang is_____ the barber’s at the moment, so you have to talk to him _____ the phone. A.in; in B.at; on C.on; at D.at; at
2 Do you expect _____to be a possibility that we shall be able to afford the particular furniture that we need. A．that B．it C．there D．one
3 下列声现象中能说明声具有能量的是 A.蝙蝠用超声波捕捉昆虫 B.马路上汽车的行驶噪声让人心烦 C.发出较强声音的喇叭能使它前面的烛焰“跳舞” D.听不同乐器弹奏同一首歌曲时能分辨出所用乐器
4 When we heard the gun fire, we all stood still and shook with _______. A．fear B．a fear C．fears D．the fear
5 城镇化是我国现代化进程中的一个基本问题。目前，我国的城镇化率过半，未来相当长一段时期内还需要继续推进城镇化。专家表示，推进城镇化不可能走单一发展模式。这是因为(　　) ①不同事物具有不同矛盾　 ②同一事物在发展的不同过程和阶段特点不同　 ③事事有矛盾，时时有矛盾 ④主要矛盾决定事物发展的进程 A．①② B．①③ C．②④ D．③④
6 As computers become more and more popular in China, Chinese are increasingly relying on computer keyboards to input Chinese characters. But if they use the computer too much, they may end up forgetting the exact strokes(笔画) of each Chinese character when writing on paper. Experts suggest people, especially students, write by hand more. Do you write by hand more or type more? In Beijing, students start using a computer as early as primary school. And computer dependence is more widespread among university students. Almost all their assignments and essays are typed on a computer. All the students interviewed say they usually use computers. It"s faster and easier to correct the mistakes if using a computer. And that’s why computers are being used more and more often in modern education. But when people are taking stock in computers increasingly, problems appear. “When I"m writing with a pen, I find I often can’t remember how to write a character, though I feel I"m familiar with it.” “I"m not in the mood to write when faced with a pen and paper.” Many students don’t feel this is something to worry about. Now that it"s more convenient and efficient to type on a computer, why bother to write by hand? Many educators think differently. Shi Liwei , the headmaster of a famous primary school in the capital said, “Chinese characters enjoy both practical and aesthetic (审美的) value. But those characters typed with computer keyboards only maintain their practical value. All the artistic beauty of the characters is lost. Besides, handwriting contains the writer"s emotion. Through one"s handwriting, people can learn one"s thinking and personality. Beautiful writing will give people a better first impression.” To encourage students to write more, many primary schools in Beijing have made writing classes compulsory and in universities, some professors are asking students to turn in their homework and essays written by hand. 小题1:Which of the following can be the best title for the passage? A．The Importance of Typing B．Practical and Aesthetic Value of Chinese Characters C．Writing by Computer Will Replace Writing by Hand D．To Type or to Write by Hand 小题2:The students interviewed prefer to type on a computer mainly because_______. A．they can correct the mistakes quickly and conveniently B．they are usually asked to e-mail their homework and essays C．they find it hard to remember how to write a character D．computers have become a trend and fashion in China 小题3:Which of the following statements is NOT true about advantages of handwriting? A．Handwriting contains the writer"s emotion. B．Handwriting can impress people well and build their self-confidence. C．The writer"s thinking and personality are shown in his or her handwriting. D．Chinese characters enjoy both practical and aesthetic value. 小题4:The underlined phrase in Paragraph 3 probably means________. A．getting bored with B．becoming crazy about C．becoming dependent on D．getting curious about
7 提高产品质量的有效途径是 A．增大产品包含的价值 B．提高产品的社会劳动生产率 C．增加产品的科技含量 D．减少产品的社会必要劳动时间
8 如图所示，在某一真空空间，有一水平放置的理想平行板电容器充电后与电源断开，若正极板 A保持水平沿竖直方向做微小往复运动时，恰有一质量为 m带负电荷的粒子(不计重力)以速度沿垂直于电场方向射入平行板之间，则带电粒子在电场区域内运动的轨迹是(设负极板 B固定不动，带电粒子始终不与极板相碰) A．直线 B．正弦曲线 C．抛物线 D．向着电场力方向偏转且加速度作周期性变化的曲线
9 假设一小型宇宙飞船沿人造地球卫星的轨道在高空中做匀速圆周运动，若从飞船上将一质量不可忽略的物体向与飞船运行相反的方向抛出，则( ) A．物体和飞船都可能按原轨道运动 B．物体和飞船可能在同一轨道上运动 C．物体的轨道半径可能减小，而飞船的轨道半径一定增大 D．飞船在新轨道上运动时的速度必然大于原轨道上的速率
10 关于地球形状的叙述，正确的是 A.棋盘似的正方体 B.倒扣的盘子 C.不规则椭球体 D.圆形