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题目列表(包括答案和解析)

24、家庭厨房就是一个化学小世界,包含着许多化学知识,回答下列问题:
(1)大米、面粉的主要成分都是
淀粉
,食盐的主要成分是
氯化钠

(2)茶叶、肉松、膨化食品等常采用真空或充气包装,所充入的气体可能是
氮气、二氧化碳等

(3)味精是烹制菜肴的调味品,味精的鲜味与溶液的酸碱度有关,当pH为6~7时鲜味最强;味精的鲜味还与温度有关,其水溶液经120℃以上长时间加热,不仅鲜味消失,而且生成对人体有害的焦谷氨酸钠.据此,下列认识不正确的是
A
(填字母).
A.谷氨酸钠在加热条件下生成焦谷氨酸钠是物理变化
B.菜烧熟起锅后再放味精比炒菜过程中加入味精更有利于人体健康
C.加入味精时,应避免在酸性或碱性较强的条件下使用
(4)若锅里的油着火了,可采取的灭火措施是
盖上锅盖
,其灭火的原理是
隔绝空气

若要用蔗糖配制蔗糖水,为使蔗糖尽快溶解,说出两种可采取的方法:①
搅拌
、②
升温
;若要除去保温瓶内胆中的水垢,选用厨房中的
食醋

(5)家用煤炉中的蜂窝煤有12孔、14孔,甚至16孔等多个品种,你认为孔道越
(填多、少)燃烧越充分.理由是
可燃物与氧气接触面积越大,燃烧越充分

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24、(1)指出下列属于溶液的溶液中的溶质和溶剂:
A、水银;B、碘酒;C、氯化钠注射液
溶质:
碘,氯化钠
,溶剂:
酒精,水

(2)在餐桌上,当我们发现某种汤很淡时,通常的做法是
加盐
.这个过程中一定不变的是
A
,一定变大的是
BCD
.(请填下列选项中的字母)
A、水的质量;B、汤的质量;C、盐的质量;D、盐的质量分数
(3)用400g溶质质量分数为40%的氢氧化钠溶液,配制成溶质质量分数为16%的氢氧化钠溶液,需要加入水的质量是
600g

(4)如图所示,充满空气的集气瓶的瓶塞上同时插有一支盛有水的小试管和一支U形管.向小试管里加入一定量氢氧化钠固体,则U形管内液面变化情况是
左侧液面下降,右侧液面上升

原因是
氢氧化钠溶于水放出热量,使集气瓶内气体温度升高,压强增大

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24、下表是部分元素的原子结构示意图、主要化合价等信息
请完成以下填空:
(1)与铝原子的最外层电子数相同的原子是
B
(填元素符号).
(2)核电荷数为11元素形成的离子符号是
Na+
;其氧化物化学式是
Na2O

(3)原子序数为12和16的元素组成化合物的化学式
MgS

(4)请你总结出此表中的原子结构与元素化合价或周期数的关系
原子的电子层数等于周期数(其他合理答案也给分)
(任写一条).

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(1)24.5克H2SO4的物质的量是______mol,
(2)11克CO2的物质的量是______mol,
(3)2.5molNa2CO3的质量是______g,
(4)1.5molH2O的质量是______g;
(5)1.806×1023个CO2的质量为______g,
(6)9.03×1023个H2SO4的质量为______g,
(7)49g硫酸中含有______个氧原子,
(8)48g甲烷中含有______个氢原子;
(9)某混合物由NaCl、MgCl2、AlCl3组成,已知Na、Mg、Al三元素的质量之比23:16:9,则NaCl、MgCl2和AlCl3物质的量之比为______.

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完型填空(共20小题;每小题1分,满分20分)
阅读下面短文,掌握其大意,然后从四个选项(A、B、C和D)中,选出最佳选项。
"Hey, Tahlia! How's the model?"
I had just taken a bite of my hot dog __21__ I heard a familiar voice yelling at me from across the crowded school yard. I saw a group of popular girls who were all __22__.
"What kind of __23_ are you going to do? An ad for a Frankenstein movie?" More laughter. My stomach twisted into a tight knot. How could they humiliate (羞辱) me like this, __24__ the entire school? As I walked into the cafeteria, I __25__ the dark scars on my right hand.
At 9 months old, I knocked over a tea pot and dumped boiling water allover my hands and stomach. My parents __26__ me to the hospital, but I had to have skin graft (移植) operation. I was in so much pain! But what __27__ me most were the cruel things people said about how I looked, __28__ that day at lunch.
The girls were being supermean to me because they'd heard I was considering doing some modeling. A close friend had suggested that I shouldn't let my scars limit me and that I might __29__ a good model.
But after that __30__ at school, I was sure I'd made a huge mistake. Upon arriving home, I covered the mirror with a blanket, fell on my bed and sobbed.
The next day, I __31__ myself to go to school. At lunch my best friend Jesse tried to encourage me: "You can't __32_ forever, Tahlia. So what if you have a few scars? Just go outside and show them that you're just as good as they are." Although I knew he was right, I couldn’t __33__ standing up for myself like that.
However, that night as I sat on the bed, my friend's words replayed in my mind. I'm __34__ hiding from myself, I thought. How stupid! Slowly, I stood up, walked over to the __35__, and tossed the blanket aside. There, in the mirror I saw a slim, dark-haired, blue-eyed girl, looking just fine, __36__ with a few scars.
The next day I wore a comfortable T-shirt to school. What's more, I had lunch outside the cafeteria, __37__ beside those mean girls. They were shocked that I should dare to walk into their territory. I felt __38_ too—free and happy.
Sometimes people still look at me strangely. They __39_ and stare, but I don't let it get to me. I have applied to several modeling companies, and at least one company is considering me for jobs. Maybe I'll never __40_ posing on the runway, but I do know one thing: I'm done.
【小题1】
A.as B.when C.while D.before
【小题2】
A.applauding B.cheering C.laughing D.quarreling
【小题3】
A.modeling B.writing C.drilling D.acting
【小题4】
A.in spite of B.in view of C.in terms of D.in front of
【小题5】
A.looked into B.searched for C.wondered aboutD.glanced at
【小题6】
A.presented B.sent C.rushedD.handed
【小题7】
A.hurtB.beat C.disappointed D.puzzled
【小题8】
A.for B.like C.on D.after
【小题9】
A.impressB.make C.consult D.defeat
【小题10】
A.effect B.phenomenon C.challenge D.scene
【小题11】
A.forced B.expected C.reminded D.preferred
【小题12】
A.apologize B.beg C.hide D.complain
【小题13】
A.consider B.imagine C.appreciate D.resist
【小题14】
A.hardly B.ever C.even D.gradually
【小题15】
A.blanket B.bed C.chair D.mirror
【小题16】
A.while B.though C.but D.because
【小题17】
A.right B.still C.therefore D.anyhow
【小题18】
A.sensitive B.uncomfortable C.different D.tense
【小题19】
A.compare B.associate C.wave D.whisper
【小题20】
A.give up B.end up C.put up D.set up

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