摘要:47:√48:√49:√50:√51:×52:×53:√54:×

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进入9年级学习化学,我们亲身体验了一系列的探究实验,感受到了化学的无穷魅力。覃浪在回顾整理下列实验中提炼了许多探究方法。

实验一、探究二氧化碳与水的反应(取四朵用紫色石蕊溶液染成紫色的干燥的小花,进行下图所示实验)

 

 

实验现象:(I)、(IV)中的小花变红。

设计(Ⅱ)、(Ⅲ)实验的目的是:  43   

该实验的探究方法是:设计分析  44   (填“A”或“B”或“C”,获得结论。

A.仅一个单因素的实验         

B.有多种因素的对比实验 

C.用前面实验的生成物继续实验

实验二、验证二氧化碳与氢氧化钠溶液也发生了反应

我们知道,二氧化碳能使澄清石灰水发生反应生成碳酸钙而变浑浊。彩云同学查阅资料发现:氢氧化钠与氢氧化钙化学性质十分相似,也能与二氧化碳发生反应,但此反应无明显实验现象,其反应的化学方程式为:   45   。她为了能证明氢氧化钠与二氧化碳在溶液中确实发生了反应,设计了如下方案。请你将她设计的方案补充完整:

 

 

实验步骤和方法

实验现象

实验结论

启示

方案1

向一个软塑料瓶中充满二氧化碳,再注入少量氢氧化钠溶液,盖紧瓶盖,摇动塑料瓶。

46

47

从反应物二氧化碳的减少(压强减小)来判断反应的发生

方案2

48

49

50

从生成物的存在来判断反应的发生

 

官龙同学认为彩云同学设计的方案1中,不能得出CO2与氢氧化钠是否确实发生了反应,理由是什么?  51  

 

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进入9年级学习化学,我们亲身体验了一系列的探究实验,感受到了化学的无穷魅力。覃浪在回顾整理下列实验中提炼了许多探究方法。

实验一、探究二氧化碳与水的反应(取四朵用紫色石蕊溶液染成紫色的干燥的小花,进行下图所示实验)

 

 

 

二氧化碳

 

 

二氧化碳

 

 
 

 

 

 

 


实验现象:(I)、(IV)中的小花变红。

设计(Ⅱ)、(Ⅲ)实验的目的是:   43   

该实验的探究方法是:设计分析   44   (填“A”或“B”或“C”,获得结论。

A.仅一个单因素的实验         B.有多种因素的对比实验 

C.用前面实验的生成物继续实验

实验二、验证二氧化碳与氢氧化钠溶液也发生了反应

我们知道,二氧化碳能使澄清石灰水发生反应生成碳酸钙而变浑浊。彩云同学查阅资料发现:氢氧化钠与氢氧化钙化学性质十分相似,也能与二氧化碳发生反应,但此反应无明显实验现象,其反应的化学方程式为:   45   。她为了能证明氢氧化钠与二氧化碳在溶液中确实发生了反应,设计了如下方案。请你将她设计的方案补充完整:

 

实验步骤和方法

实验现象

实验结论

启示

方案1

向一个软塑料瓶中充满二氧化碳,再注入少量氢氧化钠溶液,盖紧瓶盖,摇动塑料瓶。

46

47

从反应物二氧化碳的减少(压强减小)来判断反应的发生

方案2

48

49

50

从生成物的存在来判断反应的发生

官龙同学认为彩云同学设计的方案1中,不能得出CO2与氢氧化钠是否确实发生了反应,理由是什么?   51  

 

 

查看习题详情和答案>>

Usually, there is a teacher-parent meeting in every school year. Some students enjoy it, some don’t. Tom, a little boy invited his mother to attend his school's first teacher-parent meeting. To the little boy's __36__, she said she would go. This __37__ be the first time that his classmates and teacher __38__ his mother and he felt __39__ of her appearance. Although she was a beautiful woman, there was a severe scar (疤痕) that  40 nearly the entire right side of her face. The boy never wanted to _41__ why or how she got the scar.
At the meeting, the people were __42__ by the kindness and natural beauty of his mother __43__ the scar, but the little boy was still embarrassed and   44  himself from everyone. He did, however, get within __45__of a conversation between his mother and his teacher.
The teacher asked __46__, "How did you get the scar on your face?"
The mother replied, "__47__ my son was a baby, he was in a room that caught fire. Everyone was __48__ afraid to go in because the fire was __49__,so I went in. As I was running toward his bed, I saw a long piece of wood coming down and I placed myself over him trying to protect him. I was knocked __50__ but fortunately, a fireman came in and saved both of us." She __51__ the burned side of her face. "This scar will be __52__, but to this day, I have never __53__ what I did."
At this point, the little boy came out running toward his mother with tears in his eyes. He held her in his arms and felt a great __54__ of the sacrifice (牺牲) that his mother had made for him. He held her hand   55  for the rest of the day.
【小题1】
A.enjoymentB.excitementC.disappointmentD.surprise
【小题2】
A.wouldB.couldC.shouldD.must
【小题3】
A.noticedB.greetedC.metD.accepted
【小题4】
A.sickB.ashamedC.afraidD.tired
【小题5】
A.includedB.passedC.coveredD.shaded
【小题6】
A.hear aboutB.think aboutC.care aboutD.talk about
【小题7】
A.surprisedB.impressedC.excitedD.comforted
【小题8】
A.in sight ofB.by means ofC.by way ofD.in spite of
【小题9】
A.separatedB.protectedC.hidD.escaped
【小题10】
A.hearingB.remindingC.understandingD.learning
【小题11】
A.nervouslyB.carefullyC.seriouslyD.anxiously
【小题12】
A.AsB.Now thatC.SinceD.When
【小题13】
A.soB.muchC.quiteD.too
【小题14】
A.under controlB.out of control
C.in controlD.over control
【小题15】
A.helplessB.hopelessC.uselessD.senseless
【小题16】
A.pointedB.showedC.touchedD.wiped
【小题17】
A.beautifulB.lastingC.seriousD.frightening
【小题18】
A.forgotB.recognizedC.consideredD.regretted
【小题19】
A.honorB.happinessC.senseD.pride
【小题20】
A.quietlyB.tightlyC.slightlyD.suddenly
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