问题 选择题

溶质的质量分数为10%的氢氧化钠溶液,对其意义理解不正确的是(  )

A.100g水中溶解有10g氢氧化钠

B.10g溶液中含有1g氢氧化钠

C.溶液中溶质质量与溶剂质量的比为1:9

D.把5g氢氧化钠固体溶解在45g水中,可制成10%的氢氧化钠溶液

答案

A、100g水中溶解有10g氢氧化钠时,溶质质量分数=

10
100+10
×100%≠10%,故A错;

B、10g溶液中含有1g氢氧化钠时,溶质质量分数=

1
10
×100%=10%,故B正确;

C、假设取100g溶质质量分数为10%的溶液,溶质质量=100×10%=10g,溶剂质量=100-10=90g,所以溶质质量与溶剂质量之比=1:9

故C正确;

D、5g氢氧化钠固体溶解在45g水中,溶质质量分数=

5
5+45
×100%=10%,故D正确.

故选A

填空题
完形填空

Recently, one of my best friends, whom I've shared just about everything with since the first day of kindergarten, spent the week end with me. Since I moved to a new town several years ago, we've both always ___1___ the few times a year when we can see each other.

.Over the ___2___, we spent hours and hours, staying up late into the night, talking about the people she was ___3__ around with. She started telling me stories about her new boyfriend, about how he experimented with ___4___ and was into other ___5___ behavior. I was blown away! She told me how she had been ___6___ to her parents about where she was going and even sneaking out to see this guy because they didn't want her ___7___ him. No matter how hard I tried to tell her that she ___8__ better, she didn't believe me. Her self-respect seemed to have disappeared.

I tried to ___9___ her that she was ruining her future and heading for big trouble. I felt like I was getting ___10___. I just couldn't believe that she really thought it was ___11__ to hang with a bunch of losers, especially her boyfriend.

By the time she left, I was really worried about her and ___12___ by the experience. It had been so frustrating, I had come ___13___ to telling her several times during the weekend that maybe we had just grown too far apart to ___14___ our friendship - but I didn't. I put the power of ___15___ to the ultimate test. We'd been friends for far too long. The chance was that she ___16___ me enough to know that I was trying to save her from hurting herself. I wanted to believe that our friendship could ___17___ anything.

A few days later, she called to say that she had thought long and hard about our ___18___, and then she told me that she had ___19___ with her boyfriend. I just listened on the other end of the phone with tears of joy running down my face. It was one of the truly ___20___ moments in my life. Never had I been so proud of a friend.

1. A. worried about              B. looked forward to C. paid attention to     D. think of

2. A. weekend               B. months    C. years                D. days

3. A. working               B. falling in love    C. hanging                D. keeping in touch

4. A. books                   B. girls                  C. friends                     D. drugs

5. A. self-destructive      B. self-respecting  

C. self-confident           D. self-defensive

6. A. explaining            B. reasoning          C. declaring                  D. lying

7. A. on                        B. beside               C. around                     D. to

8. A. did                  B. deserved               C. had                       D. got

9. A. told                B. convince               C. force           D. warn

10. A. somewhere   B. everywhere               C. nowhere     D. anywhere

11. A. acceptable    B. believable            C. reliable             D. admirable

12. A. exhausted     B. surprised                  C. satisfied            D. terrified

13. A. almost         B. nearly                      C. close          D. over

14. A. stop             B. continue              C. start           D. make

15. A. love            B. friendship   C. truth          D. justice

16. A. thought        B. remembered      C. valued             D. hated

17. A. mean           B. conquer             C. tell                  D. prove

18. A. friendship    B. relationship              C. quarrel              D. conversation

19. A. broken away       B. broken down     C. broken up   D. broken out

20. A. demanding   B. challenging   C. frustrating      D. rewarding