问题 填空题

如图为实验室某浓盐酸试剂瓶标签上的有关数据,试根据标签上的有关数据

回答下列问题:

(1)该浓盐酸中HCl的物质的量浓度为__________mol·L-1

(2)在容量瓶的使用方法中,下列操作不正确的是____________(不定项选择)

A.使用容量瓶前检验是否漏水

B.容量瓶用水洗净后,再用待配溶液洗涤

C.配制溶液时,如果试样是固体,把称好的固体用纸条小心倒入容量瓶中,缓慢加水至接近刻度线1~2cm处,用胶头滴管加蒸馏水至刻度线。

D.盖好瓶塞,用食指顶住瓶塞,另一只手托住瓶底,把容量瓶反复倒转多次,摇匀。(3)甲、乙两同学欲用上述浓盐酸和蒸馏水配制250 mL物质的量浓度为0.400 mol·L-1的稀盐酸。

①每位同学各需要量取________mL上述浓盐酸进行配制。(保留小数点后一位)

②在配制过程中,甲同学存在以下不正确操作,对所配制的稀盐酸的物质的量浓度有何影响?(在横线上填“偏大”、“偏小”或“无影响”)。

a.用量筒量取浓盐酸时俯视观察凹液面          

b.定容后经振荡、摇匀、静置,发现液面下降,再加适量的蒸馏水

             

③乙同学转移溶液时操作如图所示,其中存在的错误是____________________________________________。

答案

(1) 11.9    (2)  B C   (3)①   8.4  ②a.偏小 b. 偏小

③转移液体时没有用玻璃棒引流;容量瓶用的是100mL,应该用250mL

题目分析:(1)质量分数与物质的量浓度的换算式是C=(ρ×1000×ω℅)÷M=(1.19×1000×36.5%)÷36.5=11.9(mol/L).

(2)A.使用容量瓶前检验是否漏水,正确。B.容量瓶用水洗净后,不能用待配溶液洗涤。错误。C.配制溶液时,试样要在烧杯中溶解,待恢复至室温时用玻璃棒引流到容量瓶中,缓慢加水至接近刻度线1~2cm处,用胶头滴管加蒸馏水至刻度线。错误。D.盖好瓶塞,用食指顶住瓶塞,另一只手托住瓶底,把容量瓶反复倒转多次,摇匀。符合溶液摇匀的操作要求。正确。所以关于容量瓶的使用方法中,操作错误的是B C。(3)①根据溶液的稀释公式C1V1=C2V2可求得需要的浓盐酸的体积是(250 mL×0.400 mol·L-1)÷11.9mol·L-1=8.4 ml.②a.用量筒量取浓盐酸时俯视观察凹液面,则读书偏大,所配溶液浓度偏小b.定容后经振荡、摇匀、静置,发现液面下降,再加适量的蒸馏水,会使溶液体积增大,导致浓度偏小。③该同学的错误是转移液体时没有用玻璃棒引流;容量瓶应该用250mL,不能用100mL的容量瓶。1V1=C2V2容量瓶的正确使用及误差分析等的知识。

单项选择题
阅读理解
阅读理解。
     Below is adapted from an English dictionary.
     Use the dictionary to answer the following questions.
figure / f?g? / noun, verb                            
● noun  
1. a number representing a particular amount, especially one given in official information: the trade / sales figures 
 2. a symbol rather than a word representing one of the numbers between 0 and 9: a six- figure salary 
 3. (informal) the area of mathematics that deals with adding, multiplying, etc. numbers  
4. a person of the type mentioned: Gandhi was both a political and a religious figure in Indian history.  
5. the shape of a person seen from a distance or not clearly  
6. a person or an animal as shown in art or a story: a wall with five carved figures in it  
7. the human shape, considered from the point of view of being attractively thin: doing exercise to improve one’s figure   
 8. a pattern or series of movements performed on ice: figure-skating be / become a figure of fun: be / become sb. that others laugh at  cut a…
put a figure on sth:  to say the exact price or number of sth.  a fine figure of man / woman: a tall, strong-looking and well-shaped person  figure of speech: a word or phrase used in a different way from its usual meanings in order to create a particular mental image or effect  figurehead: someone who is the head or chief in name only (with no real power or authority) 
 ● verb  
1. to think or decide that sth. will happen or is true: I figured that if I took the night train, I could be in Scotland by morning.  
2. to be part of a process, situation, etc. especially an important part: My opinion of the matter didn’t seem to figure at all.  
3. to calculate an amount or the cost of sth: We figured that attendance at 150,000.  
* figure in: to include (in a sum): Have you figured in the cost of hotel?    
* figure on: to plan on; to expect sth. to happen: I haven’t figured on his getting home so late.    
* figure out: to work out; understand by thinking: Have you figured out how much the trip will cost?  
* It / That figures!:  That seems reasonable.  

1. According to the information above, which of the following sentence is not right?
A. This year’s sales figures were quite excellent.
B. I couldn’t figure out what the teacher was talking about.
C. She was the leading figure in British politics in the 1980s.
D. He was about to speak but she put a figure on his lips to stop him.
2. —  She was coming late again for the work.
     — ______! That’s typical of her. You just can’t do anything to stop her doing that.
A. It figures her out
B. She is a figure of fun
C. It cuts a poor figure
D. It figures
3. The phrase “watch my figure” in the sentence “Don’t tempt me with chocolate; I am watching
    my figure.
” means “______”.
A. add the numbers
B. have sports
C. try not to get fat
D. watch games
4.Which underlined word in the following sentences is used as figure of speech?
A. John is fond of animals and raises a rabbit as a pet.
B. In some countries, bamboo can be used to build houses.
C. We all regard Mr. Smith as an important figure in our company.
D. I didn’t really mean my partner was a snake.