问题 实验题

某兴趣小组设计出下图所示装置来进行“铜与硝酸反应”实验,以探究化学实验的绿色化。

(1)实验前,关闭活塞b,试管d 中加水至浸没长导管口,塞紧试管c和d的胶塞,加热c,其目的是

___________________。

(2)在d中加适量NaOH溶液,c中放一小块铜片,由分液漏斗a向c中加入2mL浓硝酸。c中反应的化学方程式是__________________;再由a向c中加2mL蒸馏水,c中的实验现象是___________________。

(3)上表是制取硝酸铜的三种方案,能体现绿色化学理念的最佳方案是_________________________,原因是________________________。

(4)该小组还用上述装置进行实验证明氧化性KMnO4>Cl2>Br2,则c中加入的试剂是_________d中加入的试剂是__________,实验现象为_______________,但此实验的不足之处是_____________________。

答案

(1)检查装置气密性

(2)Cu+4HNO3(浓)==Cu(NO3)2+2NO2↑+2H2O;反应变缓,气体颜色变淡

(3)丙;耗酸量最少,无污染

(4)KMnO4;KBr溶液(含Br-的溶液);c中有黄绿色气体产生,d中溶液变为黄棕色;没有处理尾气

选择题
完形填空
A daughter complained to her father about her life and how things were so hard for her. She was      of fighting and struggling. It seemed as one problem was solved a new one appeared.
Her father, a cook, took her to the     . He filled three pots with      and placed each on a high fire. In one he placed carrots, in the second     , and in the last ground(磨碎的) coffee beans.
The daughter      waited, wondering what he was doing. In about twenty minutes he      the fire. He fished the carrots out and placed them in a bowl. He      the eggs out and placed them in a bowl. Then he poured the      out and placed it in a cup.      to her he asked, "Darling, what do you see?"
"Carrots, eggs, and coffee." she replied.
He brought her closer and asked her to      the carrots. She did and said that they were     . He then asked her to take an egg and      it. After pulling off the     , she observed the hard-boiled egg. Finally, he asked her to drink the coffee. She smiled, as she      its rich aroma(芳香).
"What does it     , Father?" she asked.
He explained that each of them had      the same adversity(逆境), boiling water, but each reacted     . The carrot went in strong and hard but then it turned softened and weak. The egg had been fragile(易碎的), but at last its inside became     . The ground coffee beans were unique, however, after they were in the boiling water, they had      the water.
"Which are you?" he asked his daughter.
When adversity knocks on your door, how do you     ? Are you a carrot, an egg, or a coffee bean?
小题1:
A.tiredB.ashamedC.fondD.proud
小题2:
A.hallB.kitchenC.living roomD.bathroom
小题3:
A.milkB.sugarC.waterD.powder
小题4:
A.riceB.eggsC.applesD.potatoes
小题5:
A.impolitelyB.carelesslyC.vengefullyD.impatiently
小题6:
A.put onB.put offC.turned on D.turned off
小题7:
A.wipedB.pulledC.cleanedD.washed
小题8:
A.wineB.potC.beansD.coffee
小题9:
A.LyingB.TalkingC.TurningD.Devoting
小题10:
A.cutB.buyC.feelD.cook
小题11:
A.softB.hardC.coldD.dirty
小题12:
A.sellB.boilC.holdD.break
小题13:
A.plugB.shellC.roadD.program
小题14:
A.madeB.tastedC.servedD.observed
小题15:
A.meanB.costC.matterD.contain
小题16:
A.facedB.studiedC.providedD.recognized
小题17:
A.finallyB.equallyC.differentlyD.successfully
小题18:
A.upsetB.hardenedC.effectiveD.accustomed
小题19:
A.wastedB.skimmedC.pollutedD.changed
小题20:
A.findB.knowC.respondD.practise