问题 问答题 简答题

配制溶液注意事项?

答案

参考答案:

(1)分析实验所用的溶液应用纯水配制,容器应用纯水洗三次以上。

(2)溶液要用带塞塞的试剂瓶盛装

(3)每瓶试剂必须有标明名称、规格、浓度和配制日期的标签。

(4)溶液储存时应注崐意不要使溶液变质

(5)配制硫酸、磷酸、硝酸、盐酸等溶液时,应把酸倒入水中。

(6)不能用手接触腐蚀性及有剧毒的溶液,剧毒废液应作解毒处理,不可直接倒入下水道。

(7)应熟悉一些常用溶液的配制方法

选择题
阅读理解

Long long ago, there was an old merchant who had three sons. “To which one shall I leave my fortune?” he wondered. “It must be to the cleverest son. But which one is the cleverest?”

He called his three sons to him. “Here is some money,” he told them, “you must each take one coin to buy something that will fill this room. Anyone who can do this shall have my fortune.”

“It is a big room,” said the eldest son.

“One coin will not buy very much,” said the second son.

But the youngest son said nothing. He stood and thought, and then he smiled, “Come, brothers,” he said, “let us go to the market.”

The eldest son bought straw with his coin. But one coin bought only a bit of straw. Even when he had spread it as much as he could, the straw covered only a corner of the room.

The second son bought sand with his coin. But one coin bought only a bit of sand. Even when he had spread it as much as he could, the sand covered only half of the floor.

“What did you buy?” the eldest son angrily asked the youngest son. “You don't have any straw.”

“Yes, what did you buy?” the second son asked angrily. “You don't have any sand.”

“I bought this,” said the youngest son.

“A candle!” cried his brothers. “What good is a candle?”

“Watch”, said the youngest son.

He lit the candle, and all at once the room was filled from wall to wall, from ceiling to floor. It was filled with light!

“Although you are the youngest, you are indeed the cleverest of my sons,” the old merchant said.

And that is how, the old merchant left his fortune to his youngest son, the one who could fill a room with light.

小题1: Who would get father's fortune?

A.The oldest son.

B.The richest son.

C.The cleverest son.

D.The silliest son.小题2: The merchant left his fortune to the son

A.who would fill the room by using something which is worthy of one coin

B.who would take care of him when he became old

C.who wanted to get his fortune

D.who got married first小题3: How do you think of the youngest son?

A.He is very clever.

B.He is very lazy.

C.He is very mean.

D.He is very diligent.小题4:  The youngest son used _____ to fill the room.

A.straw

B.candle

C.sand

D.water