四只试剂瓶中分别盛有NaNO3溶液、Na2CO3溶液、Na2SO4溶液和NaCl

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问题:

四只试剂瓶中分别盛有NaNO3溶液、Na2CO3溶液、Na2SO4溶液和NaCl溶液,就如何检验这四种溶液分别解答下列各题。

⑴在四支试管中分别取四种溶液各1mL,做下列实验。

①在四支试管中分别滴入___________,出现__________(现象)的是____________。离子方程式是_____________________________________。

②在剩余三支试管中分别滴入___________,出现__________(现象)的是____________。离子方程式是_______________________________________。

③在剩余两支试管中分别滴入___________,出现__________(现象)的是____________。离子方程式是______________________________________。

三次实验中都没有明显现象的是_______________。

⑵若所用试剂不变,只改变加入试剂的顺序,再设计一个实验方案,写出实验流程图。

考点:物质的分离离子的检验粗盐的提纯
题型:填空题

Mr. Smith likes playing cards(扑克)at night and goes to bed very late. He often oversleeps(睡过头). Mrs. Smith has to wake him up(不得不把他叫醒),so he won't be late for work.

One day,they have a big fight(打架). They do not speak to each other. In the evening,Mr. Smith gives his wife(妻子)a piece of paper. The paper says “Call me at seven o’clock in the morning”. Then he goes to bed.

The next morning,when Mr. Smith wakes up,it's already 9:00. He is very angry. He gets up and puts on his clothes. He finds(发现)another piece of paper on the table. “It’s seven o’clock. Get up!”

小题1:What does Mr. Smith like doing?

A.He likes playing cards.

B.He likes playing ball games.

C.He likes fighting.

D.He likes writing letter.小题2: Why does Mr. Smith oversleep?

A.He works very hard.

B.He can’t sleep at night.

C.He goes to bed late.

D.He watches TV too late.小题3:Why don’t they speak to each other?

A.Because Mr. Smith is ill.

B.Because they have a big fight.

C.Because they are both late.

D.Because they don’t have dinner.小题4:What time does Mr. Smith get up the next morning?

A.He gets up at 8 o’clock.

B.He gets up at 9 o’clock.

C.He gets up at 7 o’clock.

D.He gets up at 10 o’clock.小题5:What does Mrs. Smith’s paper say?

A.It says “Call me at 9 o’clock in the morning”.

B.It says “Don’t be late”.

C.It says “Get up,please

D.It says “It’s 7 o’clock. Get up”.

题型:填空题

当学习者意识到他不理解课的某一部分时,就会退回去重读困难的段落,放慢速度,这属于元认知策略中的()。

A.谋划策略

B.调节策略

C.监视策略

D.组织策略

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关于麻醉前用药的目的哪项是正确的()

A.解除焦虑,充分镇静和产生遗忘

B.稳定血流动力学和内环境

C.提高痛阈,减少麻醉药需求量

D.抑制呼吸道腺体分泌,保持呼吸道通畅

E.以上全部

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需申请到货地检验检疫机构鉴定的残损商品,应在索赔期满( )前申请鉴定。

A.5天
B.10天
C.15天
D.20天

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某市烟草公司,月销量在15万支以上的客户共销售卷烟3600万支,占该月总销量的7%;月销量10-15万支的客户共销售卷烟12500万支,占该月总销量的24.3%。这种销售分析方法称为()。

A、按产品分类的分析

B、按区域分类的分析

C、按客户分类的分析

D、市场占有率分析

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