问题 问答题

根据下列装置图,按要求回答有关问题:

(1)实验室制取二氧化碳的发生装置是______(填字母),反应的化学方程式为______.

(2)若选用右图装置收集二氧化碳气体时,气体应从______端进.如何检验该气体(用化学方程式表示)______

(3)实验室常用加热氯化铵与碱石灰固体混合物的方法来制取氨气(NH3),则制取氨气的发生装置应选用______(填字母).收集氨气的装置只能用D,而不能用C或E.由此可知氨气应具有的性质是______.

答案

(1)用大理石和稀盐酸制取二氧化碳属于固体+液常温型的反应,不需加热,所以可在B装置中制取二氧化碳,其反应的化学方程式为:CaCO3+2HCl═CaCl2+H2O+CO2↑;

(2)二氧化碳的密度比空气大,所以应该选用向上排空气法,如果用C装置则应该从a进入;

(3)根据收集气体的收集方法的选择依据可以知道,氨气不能用C即排水法收集,可以知道氨气可以溶于水,不能用E即向上排空法收集,可以知道氨气的密度比空气小.

故答案为:

(1)B;CaCO3+2HCl═CaCl2+H2O+CO2↑;

(2)a;CO2+Ca(OH)2═CaCO3↓+H2O;

(3)A;氨气密度比空气小并且可以溶于水.

完形填空

While I was waiting to go into university, I saw in a newspaper a teaching job wanted at a school about ten miles from where I小题1:. Because I was in great need of  小题2:and wanted to do something useful, I applied(申请).
Three days later, a letter小题3:. It asked me to see the小题4:at Croydon. It proved to be a (n) 小题5:journey —a train to Croydon station, a ten-minute bus ride and then a walk of小题6:a quarter of a mile. As a result I arrived there, feeling too hot to be nervous. Clearly, the principal小题7:opened the door. He was小题8:and round.
“The school” he said, “has a group of twenty-four boys between seven and thirteen.”
I should have to teach all the 小题9:except art, which he taught himself. I should have to divide the class into 小题10:groups and teach them at three different  小题11:, and I was not小题12:at the thought of teaching maths —a subject which I didn’t do very well in at school. It was 小题13:that I had to teach them on Saturday afternoon 小题14:most of my friends would be 小题15:themselves at that time.
Before I had time to ask about my salary(薪水), he got up to his feet. “Now,” he said. “You’d better meet my wife. She is the one who really runs this school.”
小题16:
A.livedB.playedC.studiedD.worked
小题17:
A.helpB.moneyC.restD.force
小题18:
A.arrivedB.receivedC.returnedD.wrote
小题19:
A.editorB.teacherC.principalD.student
小题20:
A.comfortableB.easyC.short D.unpleasant
小题21:
A.at leastB.at firstC.at lastD.at most
小题22:
A.herself B.themselvesC.itselfD.himself
小题23:
A.badB.gladC.shortD.smiling
小题24:
A.peopleB.subjectsC.boysD.knowledge
小题25:
A.twoB.threeC.fourD.five
小题26:
A.subjectsB.lessonsC.levelsD.schools
小题27:
A.gladB.surprisedC.angryD.sad
小题28:
A.betterB.more excitingC.worseD.nicer
小题29:
A.untilB.afterC.ifD.because
小题30:
A.enjoyingB.helpingC.studyingD.arguing
单项选择题 共用题干题