问题 选择题

下列实验操作中错误的是

A.分液时,分液漏斗下层液体从下口放出,上层液体从上层倒出

B.蒸馏时,应使温度计水银球靠近蒸馏烧瓶支管口

C.配浓硫酸和浓硝酸的混酸时,应将浓硫酸慢慢加到浓硝酸中,及时搅拌和冷却

D.测溶液的PH值需先用蒸馏水润湿PH试纸,再用干燥洁净的玻璃棒蘸溶液滴在试纸上,并与标准比色卡对照

答案

答案:D

题目分析:在测定溶液的pH值时,pH试纸不能事先润湿,否则可能会产生误差,选项D不正确,其余选项都使正确的,答案选D。

点评:化学实验常用仪器的使用方法和化学实验基本操作是进行化学实验的基础,对化学实验的考查离不开化学实验的基本操作,所以该类试题主要是以常见仪器的选用、实验基本操作为中心,通过是什么、为什么和怎样做重点考查实验基本操作的规范性和准确性及灵活运用知识解决实际问题的能力。

单项选择题
阅读理解

An old man died and left his son a lot of money. But the son was a foolish young man, and he quickly spent all the money, so that soon he had nothing left. Of course, when that happened, all his friends left him. When he was quite poor and alone, he went to see Nasreddin, who was a kind, clever old man and often helped people when they had troubles.

My money has finished and my friends have gone, said the young man. What will happen to me now?

Don't worry , young man, answered Nasreddin. Everything will soon be all right again. Wait ,and you will soon feel much happier.

The young man was very glad .Am I going to get rich again then? he asked Nasreddin.

No, I didn't mean that, said the old man. I meant that you would soon get used to being poor and to having no friends.

小题1:An old man died and left his son_______.

A.nothing

B.some gold

C.much money

D.only a house小题2:When the son was________, he went to see Nasreddin.

A.short of money

B.quite poor and sick

C.in trouble

D.quite poor and alone小题3:The young man was very glad because Nasreddin said that________.

A.he would become rich again

B.he would soon feel much happier

C.he would become clever

D.he would have more friends小题4:Nasreddin meant the young man______.

A.would get rich again

B.would get used to having nothing

C.would get used to being in trouble

D.would get out of poorness小题5:What this story tells us is________.

A.that money is everything

B.that money makes the mare go

C.to save each penny

D.that misfortune tests the sincerity of friends