问题 填空题

某校化学课外小组用硫酸亚铁废液(含少量硫酸铜和稀硫酸),制备硫酸亚铁晶体并进行如下实验.制备硫酸亚铁晶体主要的操作流程如下:

请根据题目要求回答下列问题:

(1)上述操作1的名称是                   

(2)加入过量A的目的是                             

(3)判断A过量的方法是                                                    

答案

(1)过滤 (2)除尽硫酸铜和硫酸 

(3)取沉淀于试管中,加盐酸时如有气泡产生,则说明A过量

题目分析:向混合物中加入过量的铁粉时,其中的硫酸铜和铁反应生成硫酸亚铁和铜,硫酸和铁反应生成硫酸亚铁和氢气,过滤除去生成的铜和没有反应的铁粉,蒸发可以得到硫酸亚铁晶体。

(1)铁和硫酸铜反应能生成硫酸亚铁和铜,过量的铁粉和铜不溶于水,通过过滤可以把铁粉和铜从混合物中分离出来,所以上述操作1的名称是过滤,故填:过滤;

(2)加入过量A的目的是除尽硫酸铜和硫酸,故填:除尽硫酸铜和硫酸;

(3)判断铁粉过量的方法是:取沉淀于试管中,加盐酸时如有气泡产生,则说明A过量。

阅读理解

There is a wonderful story about a young girl who had no family and no one to love her.

One day,feeling very sad and lonely, she was walking through a grassland when she noticed a small butterfly caught in a thorn (荆棘) bush. The young girl carefully released the Butterfly. Instead of flying away, the little butterfly changed into a beautiful fairy. The young girl rubbed(擦) her eyes in disbelief.“For your wonderful kindness,” the good fairy said to the girl,“I will give you any wish you would like.” The little girl thought for a moment and then replied,“I want to be happy.”The fairy  whispered(耳语) in her ear. Then the fairy disappeared.

As the little girl grew up, there was no one in the land as happy as she. Everyone asked her secret of happiness .She would only smile and answer,“The secret of my happiness is that I listened to a good fairy when I was a little girl.”

When she was very old and on her deathbed ,the neighbors gathered around her,they said to her “Tell us, please,” they begged,“Tell us what the good fairy said.” The lovely old woman simply smiled and said,“She told me that everyone, no matter how secure they seemed, no matter how old or young,how rich or poor, had need of me.”

小题1:______ the girl felt sad and lonely.

A.There was nobody to love her so

B.There were many friends

C.There was nothing to do

D.Seeing the butterfly was caught小题2: Noticing the butterfly was caught by the thorn,the orphan girl ______.

A.failed to help it release from the thorn

B.felt sorrow,but she didn’t go up to help it

C.fell down on it too

D.helped the butterfly escaped from the thorn小题3: The butterfly ______ after it was saved by the little girl.

A.flied away

B.changed into a fairy

C.still died

D.was more beautiful than before小题4:The only thing that the little girl wanted was________.

A.to be rich

B.to have her own parents

C.to have a lot of friends

D.happiness

实验题