问题 实验题

欲除去硝酸钾固体中混有的少量氯化钾杂质,某学生进行如下实验操作。回答下列问题:

(1)溶解样品。该过程所需的仪器有_______________。

(2)向溶解后的溶液中加入适量的_________溶液,使氯化钾转化为__________沉淀。(填化学式)

(3)将混合液进行过滤,过滤装置和操作如图所示,指出图中的两处错误:

①_______________________;②______________________。

答案

(1)烧杯、玻璃棒

(2)AgNO3;AgCl

(3)①漏斗下端管口没有紧靠烧杯内壁;②液体没有用玻璃棒引流

阅读理解

A young American doctor was sleeping when suddenly his doorbell began to ring. It was already midnight, but what could the doctor do? He had to get up, put on his coat and go downstairs.

When he opened the door, he saw a man standing with a hat in his hand. “How do you do?” said the man,“ Can you come at once to a place out of town? It’s quite far but you have a car and I can show you the way.”

“Certainly,” said the doctor, “I’m quite ready. I can come at once.” After a few minutes the car was standing at the front door, the man got into the doctor’s car, and they drove off.

They drove on for a long time. Then the man said, “Here we are. This is my home. Now I can pay you and you can go back to town.”

“I must see the patient. How can I go back without seeing the patient?”

“There is no patient,” explained the man. “Nobody is ill. I live here, you see, and one must get home from a town, mustn’t he? There are no taxis this time of the night, but a doctor often makes night calls, so excuse me. Here is money. Thank you, doctor. Good night.”

小题1:The doctor ____ when the doorbell started to ring.

A.was sleeping upstairs

B.was sleeping downstairs

C.was working upstairs

D.was working downstairs小题2: The man asked the doctor _____.

A.to go out for a walk

B.to go to a place out of town

C.to see a patient

D.to go for a vacation小题3:They left _____.

A.on foot

B.by bike

C.by bus

D.by car小题4:What the man wanted to do was only _____.

A. to fool the doctor         B. to give the doctor money

C. to get home in the doctor’s car     D to invite the doctor to his home

小题5:The doctor must be ______ when he heard the man’s words.

A. happy          B. angry      C. sad      D cry

单项选择题