问题 实验题

某课外小组利用H2还原黄色的WO3粉末测定W的相对原子质量,下图是测定装置的示意图,A中的试剂是盐酸。

请回答下列问题。

(1)仪器中装入的试剂:B__________、C__________、D_________;

(2)连接好装置后应首先__________,其方法是_____________,

(3)“加热反应管E”和“从A瓶逐滴滴加液体”这两步操作应该先进行的是_____________。在这两步之间还应进行的操作是_____________;

(4)反应过程中G管逸出的气体是____________,其处理方法是_____________;

(5)从实验中测得了下列数据 ①空E管的质量a ②E管和WO3的总质量b ③反应后E管和W粉的总质量c(冷却到室温称量)④反应前F管及内盛物的总质量d ⑤反应后F管及内盛物的总质量e 由以上数据可以列出计算W的相对原子质量的两个不同计算式(除W外,其他涉及的元 素的相对原子质量均为已知):

计算式1:Ar(W)=_____________;计算式2:Ar(W)=_____________。

答案

(1)锌粒;水;浓硫酸

(2)检查气密性;将G弯管浸没在盛有水的烧杯中,温热烧瓶B,观察G管口,若有气泡逸出,说明装置的气密性良好

(3)先从A瓶逐滴滴加液体;检验H2的纯度

(4)氢气;在G管出口处点燃

(5)

完形填空
There was a little boy visiting his grandparents on their farm. And he was given a slingshot(S单弓) to play with out in the woods. He _     in the woods,        he could never hit the      .And getting a little discouraged, he headed back to dinner.
As he was walking back he saw Grandma's pet duck.  Just out of impulse (冲动), he let fly, hit the duck square in the head, and killed it. He was shocked and felt very sorry.In a panic, he hid the      duck in the wood pile, only to see his sister     .Sally had seen it all, but she said nothing.
After lunch that day grandma said, “Sally, let’s wash the dishes.” But Sally said, “Grandma, Johnny told me he wanted to help in the        today, didn't you, Johnny?" And then she whispered to him, “Remember, the duck?"
So Johnny       the dishes. Later Grandpa asked if the children wanted to go fishing, and     said, " I’m sorry but I need Sally to help make       ." But Sally     and said, “Well, that's all right because Johnny told me he wanted to help," and she whispered      ,“Remember, the duck?" So Sally went fishing and Johnny     
After several days of Johnny doing     his various small tasks and Sally's, he     .couldn't stand it any longer.He came to Grandma and       that he killed the duck.She bent down, gave him a      , and said, “Sweetheart,       . You see, I was standing at the window and I saw the       thing. But because I love you, I forgave you. But I was just wondering how      you would let Sally make a slave     you."
小题1:
A.walkedB.playedC.practicedD.aimed
小题2:
A.orB.andC.soD.but
小题3:
A.birdB.targetC.duckD.woods
小题4:
A.deadB.squareC.dyingD.living
小题5:
A.surveyingB.noticingC.observingD.watching
小题6:
A.toiletB.kitchenC.living-roomD.fields
小题7:
A.watchedB.droppedC.didD.made
小题8:
A.GrandmaB.GrandpaC.JohnnyD.Sally
小题9:
A.cookB.lunchC.supperD.breakfast
小题10:
A.laughedB.smiledC.criedD.wept
小题11:
A.againB.onlyC.twiceD.loudly
小题12:
A.followedB.stayedC.rememberedD.boated
小题13:
A.allB.eitherC.neitherD.both
小题14:
A.secondlyB.firstlyC.finallyD.thirdly
小题15:
A.liedB.deniedC.admittedD.spoke
小题16:
A.beatB.petC.surpriseD.hug
小题17:
A.I knowB.you knowC.he knowsD.she knows
小题18:
A.otherB.wholeC.funnyD.dull
小题19:
A./B.muchC.manyD.long
小题20:
A.ofB.forC.fromD.into
多项选择题