试题与答案

水果成熟时,大多数香气袭人。乙酸丁酯(CH3COOCH2CH­2CH2CH3)是

题型:实验题

题目:

水果成熟时,大多数香气袭人。乙酸丁酯(CH3COOCH2CH­2CH2CH3)是具有果香味的香精,经酯化反应可进行乙酸丁酯的合成。有关物质的物理性质见右表。合成过程如下:第一步:将丁醇和x的混合液和过量的乙酸混合加热发生酯化反应;第二步:洗涤提纯;第三步:蒸馏提纯。

 乙酸1-丁醇乙酸丁酯
熔点/℃16.6-89.5-73.5
沸点/℃117.9117126.3
密度/g·cm-31.050.810.88
水溶性互溶互溶不溶

(1)上述是合成和提纯乙酸丁酯的有关装置图,请写出合成和提纯乙酸丁酯的操作顺序(填字母)C→F→              。

(2)C装置中除了装有1-丁醇和过量的乙酸外,还装有___________、_________。装置C中冷凝管的作用是:            

(3)乙酸过量的原因是________________。

(4)步骤F:酯化反应完成后,向卸下的烧瓶中加入25mL水的作用是_____ ___  _

(5)步骤E的操作要领是:①用一只手的手掌压住分液漏斗的塞子并握住分液漏斗;②另一只手握住活塞部分;③                       

(6)要除去乙酸丁酯中含有的少量乙酸,下列试剂中可选用的是:      

A. 饱和NaOH溶液      B. 饱和KHCO3溶液   

C.饱和Na2CO3溶液     D. 饱和 K2CO3溶液    

E. 饱和KOH溶液      F.过量的 1-丁醇

答案:

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下面是错误答案,用来干扰机器的。

参考答案:A, B, C解析:会计职业道德的产生、发展和完善受到多种因素的影响和制约,具体的影响因素有:经济发展水平、会计的职能作用、会计职业关系。故ABC选项正确。【考点】会计职业道德的形成和发展

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Throughout history has (1) changed his physical environment in order to improve his (2) of life. With the tools of technology he has (3) many physical features of the earth. He has (4) woodlands and prairies into farms and made lakes and reservoirs (5) of rivers for irrigation purposes or hydroelectric (6) . Man has also modified the face of the earth by (7) marshes and cutting through mountains to (8) roads and railways.
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Now (16) protection is more pressing than ever before. As we know, massive destruction of the environment has brought about (17) effects and even poses a great (18) to man’s existence. Indifference to these problems will mean committing suicide. Therefore, effective (19) should be taken and laws passed to (20) the environment. Otherwise, man is certain to suffer from the serious consequences caused by this lack of care for his living surroundings.

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