问题 选择题

下列说法正确的是

A.滴定管“0”刻度在滴定管的上端

B.先将pH试纸用蒸馏水润湿后,再测定溶液的pH

C.测定中和热时,为了减少热量损失,不要搅拌溶液

D.配制稀硫酸时,先在量筒中加一定体积的水,再边搅拌边慢慢加入浓硫酸

答案

对一些常用仪器的规格及使用要注意记忆。pH试纸的使用前,不能用蒸馏水润湿,避免对原溶液稀释导致测定不准;测定中和热时,为了减少热量损失,一般采用泡沫塑料、玻璃搅拌棒;D中,稀释浓硫酸只能在烧杯中进行,量筒是量器,故只有A正确。

选择题
[ ]

A. great

B. well-known

C. popular

D. interesting

2. They had fun in the park yesterday.[ ]

A. had much time

B. were exciting

C. had a good time

D. looked for

3. I can take care of my little sister.[ ]

A. look for

B. look after

C. look at

D. look up

4. There is lots of water in the bowl.[ ]

A. some

B. many

C. much

D. a little

5.Mother often does the laundry on Sunday.[ ]

A. does the cleaning

B. washes clothes

C. goes shopping

D. does some reading

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