问题 实验题

(14分)、实验室制备甲酸铜晶体[Cu(HCOO)2·4H2O]的流程如下:

回答下列问题:

⑴小苏打和胆矾一起研磨的目的是       

⑵生成碱式碳酸铜[Cu2(OH)2CO3]的离子方程式为   __  

⑶操作a的名称是    __  ,该操作使用的玻璃仪器有  __  

⑷证明碱式碳酸铜沉淀已经洗涤充分的实验操作方法是  __  

⑸“趁热过滤”的原因是 __  

⑹用无水乙醇洗涤晶体的目的是    __   

答案

⑴加快反应速率

⑵2Cu2+ + 4HCO3 = Cu2 (OH)2CO3 ↓ +3CO2­ + H2O

⑶过滤   玻璃棒、漏斗、烧杯

⑷取最后滤出的洗涤液少许,加入盐酸酸化的BaCl2溶液,无明显现象 

⑸防止甲酸铜结晶而损失

⑹除去甲酸并减少甲酸铜晶体损失

⑴两物质均易结块,将两固体一起研磨可增大反应物的接触面积,加快反应速率

(2)由流程图可看出,两反应物在热水中生成了Cu2(OH)2CO3,同时有CO2气体生成:2Cu2+ + 4HCO3 = Cu2 (OH)2CO3 ↓ +3CO2­ + H2O

(3)固体与液体分离时可采用过滤的方法,所用的玻璃仪器包括:玻璃棒、漏斗、烧杯

(4)在生成Cu2 (OH)2CO3 的溶液中存在SO42及Na+,故可能检验SO42是否存在来判定沉淀是否洗涤干净:取滤液少许,加入盐酸酸化的BaCl2溶液,无明显现象,即可证明

(5)蒸发浓缩后甲酸铜的浓度比较高,如果冷却至常温会以晶体的形式析出,故要“趁热”过滤;

(6)甲酸可溶于乙醇中被除去,同时甲酸铜不溶于乙醇,可减小产品损失,故选用无水乙醇洗涤晶体

阅读理解

They say that cats have nine lives but our lazy old cat,PJ,had concurrent(并存的)lives and identities. He became well-known for sleeping around the neighbourhood and used to nap in the spare bedroom of elderly couple who lived three doors up from us.While I wasn’t always aware of all his liaisons, it didn’t matter as long as he always came home at mealtimes.

One day we noticed he had gained weight. We guessed he was enjoying snacks at the local takeaway shop bins and so we began to reduce the amount of his food. He didn’t seem to notice.

Some months later. we invited some new neighbours in for drinks. Not long into the evening, our new neighbor saw PJ sitting proudly on the window ledge. “You’ve got my cat!” She exclaimed, laughing.

We let her down gently, and learnt that at their house, PJ was known as Tiger. Thanks to them, he’d been receiving the royal treatment, including removing small insects from his body by spraying medicine. PJ continued living with us until a new cat and a new dog finally tested his patience. He walked out and was missing for ten days before my husband spotted him near his work. He brought our wandering cat home, but it was clear that PJ wasn’t happy. After shouting at him angrily, I let him out and he never returned.

A few months later, our new neighbour told us she’d seen PJ. It seems that an elderly neighbour had welcomed him into her home, and since taking up residence he’d doubled in size and been given his own sitting – room chair to lie. The two had become very fond of each other, ever since he’d followed her home. What a smart cat.

小题1:By exclaiming “You’ve got my cat,” the neighbour implied that           .

A.she admitted the eat belonged to that author

B.the author had stolen the lovely eat PJ

C.she was surprised at seeing the cat there

D.she was very angry with the author小题2:What does the underlined word “He” in Paragraph 4 probably refer to?

A.The cat PJ

B.the author’s husband

C.a new neighbour

D.a neighbour’s husband小题3:It can be inferred from the passage that           .

A.the cat had visited all the neighbours before leaving

B.the author found the cat had gained some weight

C.The author couldn’t provide the cat with medical care

D.the neighbours loved the cat PJ very much

名词解释