问题 实验题

“在学校的元旦联欢会上,某同学表演了“水能生火”的魔术.他向包有过氧化钠(Na2O2)粉末的脱脂棉上滴水,脱脂棉燃烧起来。”小颖看到这段话后非常感兴趣,她和同学们一起对该问题进行了一系列的探究。

[提出问题]过氧化钠与水反应生成了什么物质?为什么脱脂棉会燃烧?

[猜想]①可能有一种气体和另一种物质生成

②反应过程中可能有能量变化

[设计装置]如图所示

[实验探究]

实验一:探究反应后生成的气体是什么?

(1)打开上图装置中分液漏斗的活塞,控制滴加水的速度,观察到试管内有气泡产生,用带火星的木条靠近P处,木条复燃.说明生成的气体是________;

(2)实验中,还观察到伸入烧杯中的导管口有气泡冒出,请解释产生该现象的原因:_____________。

实验二:探究反应后生成的另一种物质是什么?

(3)小明猜想另一种物质是Na2CO3,小军认为不可能,为了证实小军的看法,请你设计一个证明CO32-不存在的实验:

(4)小军取反应后所得的溶液于试管中,滴入无色酚酞试液,发现试管中的溶液变成红色,说明反应后所得的溶液呈______性;

[表达]小军根据实验探究的结果,写出了过氧化钠和水反应的化学方程式为____________。

答案

(1)氧气

(2)过氧化钠与水反应放出热量

(3)

(4)碱

[表达]2Na2O2+2H2O=═4NaOH+O2

完形填空
“BANG! BANG!” Setting off firecrackers(爆竹), which has been the most typical custom on the Spring Festival, is the happiest part of the Festival for most Chinese kids. They light the fuse(导火线) nervously, run away in a hurry, cover their ears with their hands and watch the colorful display with a big smile on their faces. Faced with the beautiful scene, they feel they are the happiest ones in the world as if they had never had a more exciting experience.
While setting off firecrackers can bring kids so much fun, these firecrackers can also be dangerous. Therefore, many Chinese big cities including Beijing began to ban them in the 1980s. Such an activity was completely or partially forbidden in big cities because the government took security, noise and pollution factors into consideration. As a replacement, some buy tapes with firecracker sounds to listen to, some break little balloons to get the sound too, while others buy firecracker handicrafts to hang in the living room.
This year good news came for teens in Beij ing. The ban on firecrackers was cancelled on September 9, 2008. It will add much fun to the coming Spring Festival in tile capital. Hearing the news, many kids were wild with joy.
According to Chinese custom, lighting firecrackers is a must during the Spring Fesrival. People believe the sound of the firecrackers drives away demons(恶魔) and bad luck for the coming year. Their beautiful colours and sound also bring much excitement during this most important traditional Chinese festival.
Since the ban, people complained that the Spring Festival was too quiet and not traditional enough. Children lost the fun and grown-ups lost their childhood memories.
Some even worried that if the ban continued, the next generation would only know the custom of lighting firecrackers through books. This would be a great loss for tradition.
Everybody knows that we can’t give up eating for the slight risk of choking(因噎废食). So in recent years, many cities have resumed the old custom at the request of local residents. This year Beijing kids will also be able to join in.
However, every year there are kids injured by setting off fireworks in a dangerous way. So while enjoying yourself, please bear safety in mind.
Don’t light fireworks among crowds, inside a bottle or with a part of your body right over it.
No matter how much fun firecrackers are, the most important thing is to keep away from danger. We wish every kid an exciting and safe Spring Festival!
Title:Firecrackers back in Beijing on the Spring Festival
小题1:  
for setting off firecrackers
☆It is the most typical custom of the Chinese.
☆The sound of the firecrackers is 小题2:   to drive away demons and bad luck.
☆Their beautiful colours and sound also make people 小题3:  .
Fun for kids
☆Feeling nervous and running away 小题4:   when lighting the fuse
☆Covering the ears with hands and 小题5:   the colourful display joyfully
小题6:  on the ban
☆It is very dangerous for people and their properties.
☆Its noise and smoke cause heavy 小题7:  .
Complaints about the ban
☆Much fun for kids will be 小题8:   .
☆It’s difficult for grown-ups to remember their childhoods.
Return of firecrackers
☆The government 小题9:   the ban on Septmnber 9, 2008.
☆If taking proper 小题10:   measures, Beijing kids will enjoy an exciting Spring Festival this year.
 
单项选择题

阅读下文,完成下列4题。

近两三年,一幅中国山水画,在美国被新闻报纸炒得沸沸扬扬,引起社会广泛关注,这就是传为五代董源的《溪岸图》。

《溪岸图》是一幅较早期的中国山水画应毫无疑问,而且它还是早期山水画中属保守的一派。其内容描写隐逸文人,充满着山居田园生活情趣。画中主人与妻子儿女在一起,庭院中有女仆捧着盘子似送果食,柴门外有耕作归来的男仆,路上有行人。这些细节的安排,是后来同类山水画所不具备的。细节的描写使我们想起了陶渊明《归去来兮辞》中的诗句。“童仆欢迎,稚子候门”,画中有仆人、稚子。“云无心以出岫,鸟倦飞而知还”,画中有飞鸟。“农人告余以春及,将有事于西畴”,画中穿蓑衣戴斗笠、肩负有犁的仆人,应是开春耕地回来。“木欣欣以向荣,泉涓涓而始流”,画中除葱茂的树木外,奔流的泉水亦非常突出。“登东皋以舒啸,临清流而赋诗”,画中主人倚坐在水榭栏杆之外,回首面向河水似有所思。如此等等,如果不是着意画陶诗,那也是深受陶诗影响。据《宣和画谱》卷十一记载,山水画家中有孙可元者“好画吴越间山水,笔力虽不豪放,而气韵高古,喜图高士幽人、岩居渔隐之趣。尝作《春云出岫》,观其命意,则知其无心于物,聊游戏笔墨以玩世者,所以非陶潜、绮皓之流,不见于笔下”。在御府收藏他的十二幅作品中,第一幅便是《陶潜归去来图》。这些话如果用来评价《溪岸图》也十分吻合,特别是关于艺术特点的“笔力”和“高古”的说法。而对董源,《宣和画谱》的描述是:“大抵元(这里指董源)所画山水,下笔雄伟,有崭绝峥嵘之势,重峦绝壁,使人观而壮之。”“然画家止以着色山水誉之,谓景物富丽,宛然有李思训风格,今考元所画,信然”。而沈括《梦溪笔谈》论其用笔特点是:“其用笔草草,近视之几不类物象,远观则景物粲然,幽情远思,如睹异境。”晁补之《鸡肋集》“跋董元画”亦赞成沈括的说法。既然这样,可以大胆一点,把《溪岸图》叫做《陶潜归去来图》,寄之孙可元名下。按《宣和画谱》已不知孙可元“何许人”,而“好画吴越间山水”,可推之大约为江南人,生活在北宋初年。他的名字与作品在南宋之后已无人知,名气不堪与董源相匹。有人怀疑《溪岸图》款字为后添,或许孙可元之“元”,与董元(源)之“元”有一字之同,所画又为江南景色,后添款字为宋、元间画估之所为,亦有可能。

以下不属于作者认为《溪岸图》为孙可元所作理由的一项是()。

A.画中细节的安排是后来同类山水画所不具备的。

B.好画吴越间山水,笔力虽不豪放,而气韵高古。

C.喜图高士幽人、岩居渔隐之趣,非陶潜、绮皓之流,不见于笔下。

D.画中细节的描写使人们想到陶渊明《归去来兮辞》中的诗句。