题干

对氯苯甲酸是合成非甾族消炎镇痛药的中间体,还能用于燃料和浓药的合成,实验室中制备对氯苯甲酸的反应、装置图如图2:

常温条件下的有关数据如表所示:

相对分子质量

熔点/℃

沸点/℃

密度/g•cm3

颜色

水溶性

对氯甲苯

126.5

7.5

162

1.07

无色

难溶

对氯苯甲酸

156.5

243

275

1.54

白色

微溶

对氯苯甲酸钾

194.5

具有盐的通性,属于可溶性盐

实验步骤:在规格为250mL的装置A中加入一定量的催化剂、适量KMnO4、100mL水;安装好装置,在滴液漏斗中加入6.00mL对氯甲苯,在温度为93℃左右时,逐滴滴入对氯甲苯;控制温度在93℃左右,反应2h,过滤,将滤渣用热水洗涤,使洗涤液与滤液合并,加入稀硫酸酸化,加热浓缩;然后过滤,将滤渣用冷水进行洗涤,干燥后称量其质量为7.19g.

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阅读下面短文, 从短文后各题所给的四个选项(A、B、C、D)中, 选出可以填入空白处的最佳选项。

    William Franklin came to my class half a year ago.But from his first day here,he 1 himself in his own world and he never spoke to others.As his teacher,I tried to start a talk with him but 2.It seemed as if he just didn't want to break his 3.

    After the Thanksgiving holiday,we received the news of the4Christmas collection of money for the 5 in our school."Christmas is a season of 6,"I told my students."Some poor students in our school might not have a 7 holiday.By giving a little money,you will help 8 some toys,food and clothing for these needy students.We will 9 the collection tomorrow." 

    The next morning, 10 ,I found out almost everyone had 11 this matter except Willard Franklin.He came up to my desk with his head down. 12 ,he dropped two coins into the small box."I don't need milk for lunch,"he said in a 13 voice.

    After school I couldn't help sharing what had 14 in the morning with our headmaster."I may be wrong,but I 15 Willard might be ready to become part of our class. "I am 16 to hear that," he nodded."And I just received a list of the poor families in our school who most need 17 .Here,take a look at it."

    As I sat down to 18 ,I found Willard Franklin was at the top of the list.At that moment,I felt I really 19 Willard for the first time:a cold face with a warm heart.From this 20 ,I also learnt that whether rich or poor,every child has a kind heart.