氢氧化钠与酸、二氧化碳反应没有明显现象。小军和小晴两位同学想用实验证明氢氧化钠能

题型:实验题

问题:

氢氧化钠与酸、二氧化碳反应没有明显现象。小军和小晴两位同学想用实验证明氢氧化钠能与盐酸、二氧化碳反应,他们做了以下探究过程。    

【查阅资料】通常状况下,1体积水能溶解1体积二氧化碳。    

【设计实验】小军设计了两个实验进行验证,请你帮他完成下列实验报告。

【反思交流】小晴认为:小军设计的上述两个实验都有缺陷,不足以证明氢氧化钠能与盐酸和二氧化碳反应。请你分析:

(1) 小军的第一个实验的缺陷是________________,应改为_____________。

(2) 小晴用上述小军第二个实验的装置和药品,验证氢氧化钠可以与二氧化碳反应,她的设计方案是:分别量取40 mLNaOH和Ca(OH)2溶液放入A、B中,___________________________________,此实验可以说明氢氧化钠和二氧化碳发生了反应。  

【实验结论】通过小晴的实验,证明了氢氧化钠可以与盐酸和二氧化碳反应。

考点:设计实验和科学探究
题型:实验题
It was Mother's Day. John was so busy with his work that he had ___1___time to return home. When he passed by a flower shop in the evening, he got an idea. "I'll send Mum some roses ."
___2___John was picking his flowers, another young man went inside. "How many roses can I get for only five dollars, Madam?" he asked. The assistant Nancy was trying to tell him roses were as ___3___as forty dollars a dozen . Maybe he would only buy some carnations.
"No, I have to have red roses. " He said, "My mum was badly ill last year and I didn't spend much time with her. Now I want to get something special, it has to be roses ___4___rose is her favorite. "
After hearing it, John said he would pay the rest of the money for the young man. When the young man took the roses, he almost jumped into the air and ran out of the shop. John was quite excited to see that. Then John took out his money and___5___his roses and asked the assistant to send them to his mother.
As he walked out, he saw the young man crossing the street and going into a___6___. But soon he found it was not a park but a cemetery. Crying, the young man___7___put down the roses," Mum, oh, Mum, why didn't I tell you how much I loved you? God, please help ___8___find my mum and tell her I love her..."
___9___thinking anything, John turned and quickly walked back to the shop. He would take the __10____home himself.
小题1:
A.noB.enoughC.muchD.more
小题2:
A.AfterB.JustC.WhileD.Before
小题3:
A.cheapB.beautifulC.expensiveD.awful
小题4:
A.becauseB.soC.butD.when
小题5:
A.looked afterB.took awayC.paid forD.got out
小题6:
A.shopB.parkC.train stationD.hospital
小题7:
A.loudlyB.happilyC.carefullyD.hardly
小题8:
A.himB.herC.meD.them
小题9:
A.AsB.WithC.withoutD.For
小题10:
A.carnationsB.moneyC.scarfD.flowers
题型:实验题

绝经妇女骨质疏松症的治疗大法下列哪些是正确的()

A.滋养肝肾

B.补肾填精益髓

C.滋阴清热,补肾强筋

D.补肾壮阳、益髓健骨

E.益肾健脾

题型:实验题

信用社2004年3月10日为某开户单位办理银行承兑汇票贴现业务,票面金额为100000元(不附息票据),期限为6个月,贴现利率为6.6%,请计算贴现利息,并编制会计分录。

题型:实验题

在Windows 9x/2000/XP中,同一个文件存储在软盘上或硬盘上,它所占用的磁盘空间大小通常是上______的。

题型:实验题

下列变量是定量变量的有()。

A.天气温度

B.月收入

C.上证指数

D.市场上的蔬菜价格

E.工厂每月生产的产品数量

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