摘要:第一部分 选择题 第1题一第10题.每小题只有一个选项符合题意.每小题1分.共10分.1.下列过程发生化学变化的是 A.花香四溢 B.海水晒盐 C.粮食酿酒 D.冰雪消融
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(2009?丰台区一模)根据下列每小题提出的问题填空.
(1)填写化学符号或化学符号的意义:
(2)请在下表中写出有关的化学方程式,并回答有关的问题.
(3)科学家最近在-100℃的低温下合成一种化合物X,此分子的模型如下图,其中每个“●”代表一个碳
原子,每个“○”代表一个氢原子.下列说法中不正确的是______.
①该分子可用C5H4表示;
②该物质中碳元素的质量分数是93.75%;
③该分子中的氢原子与碳原子的质量比是4:5;
④等质量的该物质与甲烷相比,燃烧时消耗的氧气更多.
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(1)填写化学符号或化学符号的意义:
| 化学符号 | 2N | |
| 意义 | n个水分子 |
| 用途 | 化学方程式 | 相关问题 |
| 生石灰常用作某些食品的干燥剂 | ______________ | 此反应_________(填“吸热”或“放热”) |
| 小苏打可治疗胃酸过多 | ______________ | 基本反应类型 _______________ |
①该分子可用C5H4表示;
②该物质中碳元素的质量分数是93.75%;
③该分子中的氢原子与碳原子的质量比是4:5;
④等质量的该物质与甲烷相比,燃烧时消耗的氧气更多.
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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.
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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.
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下列实验方案不可行的是 ( )
A.由氧化铁制取氢氧化铁:
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B.由氧化钙制取氢氧化钠溶液
C.除去氯化钠溶液中少量的碳酸钠
D.除去氯化钾固体中少量的二氧化锰
二、选择题(本题包括5小题,每题2分,共10分,每小题有一个或两
查看习题详情和答案>>选择填充题(本大题包括5小题,每小题2分,共10分。先在A、B、C中选择一个正确选项填在相应的括号里,然后在D处再补充一个符合题意的答案。每小题的选择与填充各1分)
在化学元素里,有4种元素约占人体的96%以上,被称为人体必需元素中的常量元素。下列元素肯定属于人体常量元素的是………………………………………………………………………………………………( )
A、C B、Fe C、Zn D、
查看习题详情和答案>>(1)下列认识不正确的是(填写字母代号)
A
.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
D.研究问题的一种有效方法是通过实验
(2)小明还想对此味精进一步探究,想测定此味精中氯化钠的含量.
[查阅资料]NaCl+AgNO3=AgCl↓+NaNO3,谷氨酸钠的存在不影响NaCl性质.
[实验过程]第一步:称取该味精样品10.0g,并溶于蒸馏水
第二步:加入过量的硝酸银溶液,过滤
第三步:用蒸馏水反复洗涤沉淀多次
第四步:将沉淀烘干、称量,测得固体质量为5.74g
根据上述实验步骤回答下列有关问题:
①过滤操作所需要的仪器除烧杯、铁架台(带铁圈)、玻璃棒外,还需要的玻璃仪器是
漏斗
.②试通过计算确定此样品中NaCl质量分数?