问题 填空题

食盐在生活中具有广泛的用途。

(1)常温下,用氯化钠和水配制100 g溶质质量分数为5%的溶液时,必须用到的仪器有:托盘天平、药匙、胶头滴管、玻璃棒、量筒和          ,其中玻璃棒的作用是       

(2)上述氯化钠来自于粗盐提纯,粗盐提纯的主要步骤是溶解、        和蒸发。在蒸发过程中,待蒸发皿中出现较多固体时,停止加热,这样操作的目的是       

(3)海水晒盐能够得到粗盐和卤水。卤水中含有MgCl2、KCl和MgSO4等物质,下图是它们的溶解度曲线。

t1℃时,MgCl2、KCl和MgSO4三种物质的饱和溶液中,溶质质量分数最大的是       。将t2℃的MgCl2、KCl和MgSO4三种物质的饱和溶液降温至t1℃时,可能会析出的晶体有        (填字母序号)。

A.MgCl2和KCl       B.只有MgSO4       C.MgCl2、KCl和MgSO4

答案

(1)烧杯      加速氯化钠固体的溶解

(2)过滤   利用蒸发皿的余热使滤液蒸干防止飞溅 (两点答出其一即得1分)

(3)MgCl2     C

(1)配制溶液用到的仪器有:托盘天平、药匙、胶头滴管、玻璃棒、量筒和烧杯;溶解时用玻璃棒搅拌是加速氯化钠固体的溶解

(2)粗盐提纯的主要步骤是溶解、过滤、蒸发;在蒸发操作时,待蒸发皿中出现较多固体时,停止加热,利用蒸发皿的余热使滤液蒸干,防止飞溅

(3)饱和溶液溶质质量分数的计算方法是:,所以溶解度大的,溶质质量分数就大,所以t1℃时,MgCl2、KCl和MgSO4三种物质的饱和溶液中,溶质质量分数最大的是氯化镁;将t2℃的MgCl2、KCl和MgSO4三种物质的饱和溶液降温至t1℃时,只要溶解度减小的都能析出晶体,由图示可知三种物质的溶解度都变小,都能析出晶体

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完形填空

第二节:完形填空(共20小题,每小题1.5分,满分30分)

My brother-in-law lifted out a package in which was delicate lingerie(女式内衣)“Jan bought it 8 years ago   36   she never wore it. She was   37   it for a special occasion.” He put it with the other clothes we were taking to the mortician(殡仪员). “Don't save anything for a special occasion. Every day when you're   38   is a special gift.” he said.

I remembered those words through the funeral(葬礼)and the days that followed when I helped with all the chores after Jan's sudden   39  . I thought about them on the plane returning to California. I'm   40   thinking about his words, and they've   41   my attitude towards life. I'm admiring the view   42   worrying about the weeds in the garden. I'm spending more time with my family and friends and   43   time in committee meetings.

Whenever possible, life should be an experience to   44  , not tolerate. I'm trying to recognize these moments and   45   them. “Someday” and “one of these days” are   46   from my vocabulary. If it's worth seeing or hearing or doing, I want to see and hear and do it now. I'm not sure what my sister would have done if she had known she wouldn't be here for the tomorrow that we all __47__ for granted. I think she would have gone out for her favorite Chinese food. She might have called a few former friends to apologize for past   48  . I'm guessing — I'll   49   know.

It's those little things left undone that would make me angry if I knew that my hours were __50__ . Angry because I   51   seeing good friends I was going to get in touch with — someday. Angry and __52__ that I didn't tell my husband and daughter often enough how much I truly love them.

I'm trying not to put off, or save anything that would add   53   and color to our lives. Every morning when I open my eyes, I tell myself it is   54  . Every day, every minute, every breath truly is a(n)  55   from God.

36. A. and                 B. so                     C. as                  D. but

37. A. buying                B. saving                 C. leaving              D. remaining

38. A. happy                B. healthy               C. alive                D. successful

39. A. separation             B. death                  C. disease               D. treatment

40. A. still                  B. also                   C. even                 D. therefore

41. A. changed               B. spoiled                 C. shaped                     D. held

42. A. beyond               B. besides                 C. without              D. over

43. A. most                 B. little                   C. more                 D. less

44. A. enjoy                B. share                  C. control              D. choose

45. A. ignore                B. value                 C. stress                 D. remember

46. A. disappearing           B. escaping               C. coming              D. leaving

47. A. find                  B. think                  C. take                 D. make

48. A. affairs                B. quarrels                C. hardships             D. memories

49. A. surely                 B. always                C. ever                       D. never

50. A. endless                B. abundant              C. valuable              D. limited

51. A. called off              B. gave off              C. put off                     D. took off

52. A. sorry                 B. disappointed           C. shameful             D. embarrassed

53. A. value                 B. laughter              C. imagination                 D. freedom

54. A. common               B. unforgettable                C. special               D. similar

55. A. offer                  B. promise                    C. smile                D. gift