问题 选择题

现配制100克溶质质量分数为5%的NaCl溶液,下列说法正确的是(  )

A.将氯化钠固体直接放在天平的托盘上称取5克食盐

B.用10mL量筒比用100毫升量筒量取95毫升水更精确

C.为加快固体溶液,用温度计搅拌

D.将配好的溶液倒入细口瓶中,塞紧瓶塞并贴上标签

答案

A、应将氯化钠固体放在纸上称量,防止沾到托盘上,故错误;

B、要配制100g 溶质质量分数为5%的氯化钠溶液,需要称量5g氯化钠固体,量取95ml水,应选100mL的量筒,用10mL的量筒须多次量取,误差更大,故错误;

C、为加快溶解速率需使用玻璃棒搅拌而不能使用温度计,若用温度计容易导致温度计损坏,造成试剂污染;故错误;

D、将配好的溶液倒入细口瓶中,塞紧瓶塞并贴上标签,正确;

故选D.

选择题
阅读理解

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III.阅读理解(共15小题计30分)

We drink tea every day. But more than three hundred years ago, most of the people in Europe did not know anything about tea, because it was grown in Asia. There is a story about an English sailor(水手). Once he went to India and China. When he came home, he brought some tea as a present for his mother. She told her friends about the present and asked them to a tea party.  When her friends came to the tea party, the old woman brought out some leaves and asked them to eat tea. Of course, nobody liked the tea leaves.

Just then the sailor came in.  He looked at the tea leaves on the table and asked his mother,“What have you done with the tea?”

“I boiled it as you said.”

“I threw it away, of course.” answered the woman.

“Now, you may throw away the leaves, too.” said her son.

56. Who first grew tea?

A. People in Europe.                                        B. People in Asia.

C.People in China only.                                D. People in India only.

57. The woman’s friends ________.

A. enjoyed the tea leaves very much                   B. didn’t like drinking tea

C. didn’t like the tea leaves                           D. threw away all the tea leaves

58. Before the old woman boiled the tea, ________.

A. she had learned how to enjoy it

B. her son had taught her how to drink tea

C. her son had not told her to drink the boiled water only

D. her son had not told how to eat the tea leaves