问题 填空题

某溶液含有Na+、H+、Ba2+、OH-、Cl-CO32-SO42-中的几种离子,进行如下实验

(1)取少量溶液于试管中,加入足量氯化钡溶液,产生白色沉淀,过滤后得到滤渣和滤液.

(2)向滤渣中加入稀硝酸,滤渣全部溶解并产生气泡.

(3)向滤液中滴入无色酚酞溶液,溶液呈红色.

根据上述实验判断该溶液中

①一定含有的离子是______;

②一定不含的离子是______;

③不能确定的离子是______,欲确定其是否存在,方法是:另取少量原溶液于试管中,______,若看到______,说明溶液中含的该离子.

答案

根据题干提供的信息结合物质的性质可以知道,能够和氯化钡反应生成白色沉淀的有CO32-和SO42-,钡离子能与SO42-结合产生不溶于水和稀硝酸的沉淀,根据(2)中滤渣全部溶解可以知道该沉淀为碳酸钡沉淀,从而可以判断一定不含SO42-;而(1)所得的滤液能够使酚酞溶液变红,说明该溶液为碱性,所以可以判断该溶液中含有OH-;所以可以判断在溶液中一定含有的离子为:CO32-和OH-;一定不含SO42-;由于CO32-能够Ba2+和生成沉淀,所以一定不含Ba2+,而OH-和H+能够反应生成水,所以一定不含H+;根据溶液中电荷守恒可以判断在溶液中一定含有的阳离子为Na+;而氯离子在实验中没有涉及到,所以不能判断是否含有Cl-,由于Cl-能够和银离子反应生成沉淀,且生成的氯化银沉淀难溶于稀硝酸,所以可以用稀硝酸和硝酸银来进行检验.

故答案:①CO32-、OH-、Na+

②SO42-、Ba2+、H+

③Cl-;加入适量硝酸银溶液和稀硝酸;有白色沉淀产生.

阅读理解与欣赏

阅读下面的文字,完成16~19题。

洪湖水,浪打浪

熊召政

①我曾在雨雾迷蒙的四月,航行在烟波浩淼的太湖,听忽远忽近的渔歌,看雁落平沙的远景。渐行渐远而略无歇泊,乃是因为,我觉得江南最好的花汛和鱼汛,总在桨橹不及的前渚。我亦在天高云淡的八月,翻越雪花飘飘的念青唐古拉山口,千里万里,怀着朝圣的心情,我来到地球上最高的湖泊纳木错湖,面对千万顷纤尘不飞的澄碧,我眼含热泪跪下去。在那里,我不可能得到舣舟的乐趣,但是,我知道了什么叫圣洁,什么叫宁静。它们有着溶解一切喧嚣的空灵,有着翡翠一般的冷润的颜色。

②然而现在,在这红叶摇落的暮秋,我记忆中的这些湖水,突然像风中的涟漪,一圈一圈地散去了。一只古铜色的的臂膀,奋力地摇着桨板,把我带进另一片苍茫的波心。

③映日的荷花,被炎热的夏天带走了;夕照中的芦苇,兀自用大片大片的空翠,抵抗日重一日的秋寒。突然,一只鱼鹰飞起了,被它勾起的晶莹的露珠,又飘然而下,就在溅落的那一刻,风起了。平静的湖面顿时推起层层怒涛,在这蕴蓄着闪电飘雷的雪浪中,一曲熟悉的旋律像湖鸥一样掠起:洪湖水,浪打浪……

④听着这优美的歌声,一些早已久违了的诸如苏维埃、农会、暴动、赤卫队等等词汇,顿时像眼前的浪涛一样,沉重地撞击着我的心扉。这些词汇在七十多年前,就像今天的改革、科技、WTO、民族复兴等词汇一样,组成了一个时代的全部生活。

⑤风烟滚滚的历史已经凝结成了国旗上的五颗金星。民族的爱恨情仇已经永久镌刻在烈士纪念碑雄浑的基座上。但是,共和国的子民们,却是须臾不能忘记——苏区——这一个闪光的字眼。

⑥在中国的近代史中,洪湖给予人们的记忆,首先不是水的定义,而是革命的概念。湖边的村落与老街,曾经红旗漫卷,戈矛林立;湖上的苇丛与荷荡,曾经孕育过共和国的最初的春梦。

⑦大凡成为历史的东西,有的,令我们生发久久的惆怅;有的,其辉煌的光晕会眩迷我们的眼睛。洪湖不是这样。当它的波浪,不再随着战士的碧血一起荡漾;当它的船头,不再站立着戎马倥偬的 * * ,它仍是那么粗犷地承载着壮丽的日出,那么闲适地浸浮着中天的霜月。晚霞起时,它的水面,就会铺着一层火焰;大雪落下,它的苇花深处,仍会孵出冰清玉洁的童话。枪挑冷月的战士们走了,他们留下的空旷,又被采菱少女的笑声填满;剑啸惊涛的 * * 们走了,他们留下的故事,已成为扳罾老汉传唱的歌谣……

⑧桨声欸乃,我已在洪湖中走得很远,很远。暮色苍茫,团团野鸭,逐渐与水波合为一色,犹如芬芳的诗韵消失在唐代的酒香里;丝丝荇草,正在等待着三颗两颗渔火,犹如沙漠的旅客,正在等待甘洌的泉水。而我,也正伫立在船头等待,等待寒秋的明月破云而出,等待清朗的月辉下,另一只小舟自深浦荡出,船头上清丽的渔姑,为我再唱一遍:洪湖水,浪打浪……

小题1:.作者开篇为什么不写洪湖,却从太湖和纳木错湖写起?请概括说明。(4分)

小题2:.文章的第7段中说:“大凡成为历史的东西,有的,令我们生发久久的惆怅;有的,其辉煌的光晕会眩迷我们的眼睛。洪湖不是这样。”结合全文的内容,请阐释“不是这样”的含义。(4分)

小题3:.你认为作者在文中两次引用歌词“洪湖水,浪打浪”的用意分别是什么?请分条说明。(4分)

小题4:.任选一个角度,简要分析文中第⑧段画线句子运用的手法及其表达作用。(6分)

阅读理解

阅读理解

     Boys need friends, suffer when they don't believe they have any, and worry over the ups and downs of relationships. Many adults believe that somehow boys need friends less than girls do, in truth, though, no

boy is an island; boys value their friends throughout childhood and adolescence and are happier and

healthier when they have solid relationships with peers(同龄人).

     Despite the common belief that girls are better at relationships, most boys consider their friends a very

important part of their lives, and boys may actually be better at keeping friendships than girls are. A recent study of 10 to 15yearold boys and girls found that girls' friendships are actually more fragile. Girls tend to

say and do hurtful things to each other more frequently than boys, and girls are more hurt by the end of a

friendship.

     Boys are the living definition of the phrase "peer group"; they love games with rules, competition, and doing things together. Boys seem to enjoy, even need the opportunity to test themselves against others, and many lasting friendships begin in karate(空手道) class or on the basketball court. Competence and skill

are widely respected; being picked last for a team or left out altogether is an experience that can haunt

(萦绕心头) a boy for years.

     As boys mature, the friendship becomes even more important, and it frequently widens to include girls. During the teen years, friends can become the most important part of a boy's life-and a part in which his

parents are not included. The confusion of being a teenager leads boys to form close bonds with friends.

There is the sense for many boys that a friend is someone who is "always there for me", someone he can

trust. They may be partners in crime or partners in study, but the friendship of adolescent boys can run

surprisingly deep.

1. The common belief of adults is that boys________.

A. don't care about others as much as girls

B. don't value friendship as much as girls

C. have the same friendship as girls

D. have healthier friendship than girls

2. According to the text, boys' friendship________.

A. is usually built around active play

B. tends to be in small groups

C. can bear mutual hurt between friends

D. doesn't suffer from failure

3. The author mentions the study in the second paragraph to prove ________.

A. many people believe girls are better at relationships

B. most boys consider their friends very important

C. boys may be better at keeping friendships than girls

D. boys may be more active in a friendship

4. As a boy gets older, he tends to________.

A. widen his circle of friends to include different kinds of people

B. shift his focus from his friends to himself

C. leave his parents out of his friendship

D. be confused about what a friendship is

5. What's the best title for the text?

A. Friendships between Boys and Girls

B. Boys and Their Friendship

C. Childhood and Adolescent Friendship

D. Tips on Making Friends with Boys