问题 问答题

按要求回答下列问题:

(1)实验室制取气体时,选择气体发生装置的依据是______和______.

(2)用如图所示装置收集气体时,收集满气体的标志是______.

(3)要验证混合气体是由CO、CO2、H2、水蒸气四种气体组成,现设计实验装置图如下(注:无水CuSO4粉末遇水变蓝).请回答下列问题:

①C装置的作用是______.若去掉C装置,还会导致______.

②D装置的作用是______.

③若F、G装置顺序对调,将会导致______.

④该装置的不足之处是______.

答案

(1)实验室制气体有加热和不加热两种装置,制取装置的选择应考虑:反应的条件和反应物的状态.故答案为:反应的条件;反应物的状态

(2)用排水法收集氧气时,当气泡从集气瓶口向外冒出时,就证明氧气已经满了.故答案为:当气泡从集气瓶口向外冒出时

(3)A装置是验证水的,B装置是验证二氧化碳的,C装置是除去二氧化碳的,D装置是除去水蒸气的.F、G装置不能颠倒,否则影响一氧化碳和氢气的检验,一氧化碳有毒,因此要进行尾气处理.故答案为:①除去二氧化碳;G中石灰水变浑浊.尾气处理装置.②吸水干燥作用;③无法验证是否有氢气;④没有尾气处理装置.

改错题

短文改错。

     假如英语课上老师要求同学们交换修改作文,请你修改你同桌的以下作文。文章共有10处语言

错误,要求你在错误的地方增加、删除或修改某个单词。

增加:在缺词处加一个漏字符号(A),并在其下面写上该加的词。

删除:把多余的词用斜线(\)划掉。

修改:在错的词下画一横线,并在该词下面写上修改后的词。

注意:1. 每处错误及修改词均仅限一词; 

          2. 只允许修改10处,多者(从11处起)不记分。

Dear Editor,

     I'm writing to tell you about a food poisoning accident. Several days ago, my neighbor ate a bag of food

buying from the market. After the meal, they had stomachaches and their faces turn pale. Fortunately, one

of their friends found the accident and immediately called on an ambulance, which carried them quickly to

a hospital. After several hours' treatment they finally escaped from death. 

     As some illegal businessmen only interested in making profits to become rich quickly, we seldom care

about the necessary safety measures or care which happens to consumers. They must be charged with law.

Meanwhile, I do hope whole society can realize the important of food safety and begin taking action together

to make sure food is safe. 

                                                                                                                                         Yours, 

                                                                                                                                        Wang Ming

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判断题