下表是氯化钠、氯化铵在不同温度下的溶解度(单位:g/100g水) ①20℃时,

题型:填空题

问题:

下表是氯化钠、氯化铵在不同温度下的溶解度(单位:g/100g水)

①20℃时,氯化钠的溶解度是___________g/100g水。

②40℃时,向两只分别盛有42gNaCl和NH4Cl固体的烧杯中,各加入100g水,充分溶解后,能形成饱和溶液的物质是____________,其饱和溶液的质量为____________g。

③采用一种操作方法,将上述②中烧杯内的剩余固体全部溶解,变为不饱和溶液。下列说法正确的是_____________(填字母序号)。    

A、溶液中溶质的质量减少                         

B、可升高温度或增加溶剂

C、溶液质量不变                                 

D、溶液中溶质的质量分数减小

④农业生产常用溶质的质量分数为10%~20%的NaCl溶液来选种。现将100g25%的NaCl溶液稀释为10%的NaCl溶液,需要加水的质量为_______________g。

考点:固体溶解度饱和溶液,不饱和溶液关于溶液的计算
题型:填空题

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       Harry goes out after lunch.  He goes in the tree house.  But he can't find his football. He's sure Nick takes it away.  He doesn't know where they are playing. He comes down and begins to play with his dog Bobby.  His father comes out, with a bag in his hand.

        "Where are you going, Daddy?" asks the boy.

        "Mr.  Hill is ill," says his father.  "I'm going to see him. "

    .   Mr.  Hill has a nice garden.  There are all kinds of flowers in it.  And the boy likes to pick some there.  So he asks his father to take him there.  Half an hour later, their car stops at Mr.  Hill's gatc and an old man opens the door for them.

       Mr.  Hill is in bed.  Harry says hello to him and then comes out.  Rose, the little daughter of Mr.  Hill's, brings him to the garden and picks (摘) some flowers for him.  The boy is happy and thanks the little girl.

       "Do you feel like a cup of coffee, Harry?-  asks Rose.

       "Look at me,carcfully," says the boy.  "Do I look like one?"

1. Harry goes out in the _________.

2. Mr.  Hill is ill.  So Harry's father wants to_________Mr.  Hill.

3. Harry goes to Mr.  Hill's to get some_________.

4. Harry and his father go to Mr.  Hill's by_________.

5. _________knows Harry likes flowers and picks some for him.

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C.水膜原理;

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